Ball hiting & explosion

[Onyx]

Hi, i got two questions.

1. How to make a ball that explode only when hits a character (for example, dont explode when hit rock, or other ball)
2. I made a ball which explode on any contact, but when item is on the ground (even knife which is small) that ball always
hiting this item (height of this ball is like firen_ball) How to change that? I want that ball to evade items like knife without changing height.

Code:

<bmp_begin>
file(0-11): sprite\sys\eisen_ball.bmp  w: 40  h: 39  row: 4  col: 3
file(16-30): sprite\sys\eisen_exp.bmp  w: 159  h: 159  row: 5  col: 3
weapon_hit_sound: data\020.wav
weapon_drop_sound: data\020.wav
weapon_broken_sound: data\020.wav
<bmp_end>

<frame> 0 flying
   pic: 0  state: 3000  wait: 1  next: 1  dvx: 23  dvy: 0  centerx: 51  centery: 41  hit_a: 0  hit_d: 0  hit_j: 0
   itr:
      kind: 0  x: 22  y: 27  w: 55  h: 27  dvx: 10  dvy: -10  fall: 70  vrest: 10  bdefend: 16  injury: 45  
      effect: 2  
   itr_end:
   bdy:
      kind: 0  x: 22  y: 27  w: 55  h: 27
   bdy_end:
<frame_end>

<frame> 1 flying
   pic: 1  state: 3000  wait: 1  next: 2  dvx: 23  dvy: 0  centerx: 53  centery: 41  hit_a: 0  hit_d: 0  hit_j: 0
   itr:
      kind: 0  x: 22  y: 27  w: 55  h: 27  dvx: 10  dvy: -10  fall: 70  vrest: 10  bdefend: 16  injury: 45  
      effect: 0  
   itr_end:
   bdy:
      kind: 0  x: 22  y: 27  w: 55  h: 27
   bdy_end:
<frame_end>

<frame> 2 flying
   pic: 2  state: 3000  wait: 1  next: 3  dvx: 23  dvy: 0  centerx: 51  centery: 41  hit_a: 0  hit_d: 0  hit_j: 0
   itr:
      kind: 0  x: 22  y: 27  w: 55  h: 27  dvx: 10  dvy: -10  fall: 70  vrest: 10  bdefend: 16  injury: 45  
      effect: 2  
   itr_end:
   bdy:
      kind: 0  x: 22  y: 27  w: 55  h: 27
   bdy_end:
<frame_end>

<frame> 3 flying
   pic: 3  state: 3000  wait: 1  next: 4  dvx: 23  dvy: 0  centerx: 54  centery: 41  hit_a: 0  hit_d: 0  hit_j: 0
   itr:
      kind: 0  x: 22  y: 27  w: 55  h: 27  dvx: 10  dvy: -10  fall: 70  vrest: 10  bdefend: 16  injury: 45  
      effect: 0  
   itr_end:
   bdy:
      kind: 0  x: 22  y: 27  w: 55  h: 27
   bdy_end:
<frame_end>

<frame> 4 flying
   pic: 4  state: 3000  wait: 1  next: 5  dvx: 23  dvy: 0  centerx: 55  centery: 41  hit_a: 0  hit_d: 0  hit_j: 0
   itr:
      kind: 0  x: 22  y: 27  w: 55  h: 27  dvx: 10  dvy: -10  fall: 70  vrest: 10  bdefend: 16  injury: 45  
      effect: 2  
   itr_end:
   bdy:
      kind: 0  x: 22  y: 27  w: 55  h: 27
   bdy_end:
<frame_end>

<frame> 5 flying
   pic: 5  state: 3000  wait: 1  next: 999  dvx: 23  dvy: 0  centerx: 54  centery: 41  hit_a: 0  hit_d: 0  hit_j: 0
   itr:
      kind: 0  x: 22  y: 27  w: 55  h: 27  dvx: 10  dvy: -10  fall: 70  vrest: 10  bdefend: 16  injury: 45  
      effect: 0  
   itr_end:
   bdy:
      kind: 0  x: 22  y: 27  w: 55  h: 27
   bdy_end:
<frame_end>

<frame> 10 hiting
   pic: 8  state: 3001  wait: 0  next: 110  dvx: 0  dvy: 0  centerx: 40  centery: 43  hit_a: 0  hit_d: 0  hit_j: 0
<frame_end>

<frame> 11 hiting
   pic: 9  state: 3001  wait: 1  next: 12  dvx: 0  dvy: 0  centerx: 40  centery: 42  hit_a: 0  hit_d: 0  hit_j: 0
<frame_end>

<frame> 12 hiting
   pic: 10  state: 3001  wait: 1  next: 13  dvx: 0  dvy: 0  centerx: 44  centery: 41  hit_a: 0  hit_d: 0  hit_j: 0
<frame_end>

<frame> 13 hiting
   pic: 11  state: 3001  wait: 1  next: 1000  dvx: 0  dvy: 0  centerx: 52  centery: 40  hit_a: 0  hit_d: 0  hit_j: 0
<frame_end>

<frame> 20 hit
   pic: 8  state: 3002  wait: 0  next: 110  dvx: 0  dvy: 0  centerx: 44  centery: 43  hit_a: 0  hit_d: 0  hit_j: 0
<frame_end>

<frame> 21 hit
   pic: 9  state: 3002  wait: 1  next: 22  dvx: 0  dvy: 0  centerx: 41  centery: 43  hit_a: 0  hit_d: 0  hit_j: 0
<frame_end>

<frame> 22 hit
   pic: 10  state: 3002  wait: 1  next: 23  dvx: 0  dvy: 0  centerx: 44  centery: 41  hit_a: 0  hit_d: 0  hit_j: 0
<frame_end>

<frame> 23 hit
   pic: 11  state: 3002  wait: 1  next: 1000  dvx: 0  dvy: 0  centerx: 54  centery: 41  hit_a: 0  hit_d: 0  hit_j: 0
<frame_end>

<frame> 30 rebounding
   pic: 8  state: 3003  wait: 0  next: 110  dvx: 0  dvy: 0  centerx: 43  centery: 43  hit_a: 0  hit_d: 0  hit_j: 0
<frame_end>

<frame> 31 rebounding
   pic: 9  state: 3003  wait: 1  next: 32  dvx: 0  dvy: 0  centerx: 40  centery: 42  hit_a: 0  hit_d: 0  hit_j: 0
   opoint:
      kind: 1  x: 41  y: 42  action: 0  dvx: 0  dvy: 0  oid: 210  facing: 1
   opoint_end:
<frame_end>

<frame> 32 rebounding
   pic: 10  state: 3003  wait: 1  next: 33  dvx: 0  dvy: 0  centerx: 46  centery: 39  hit_a: 0  hit_d: 0  hit_j: 0
<frame_end>

<frame> 33 rebounding
   pic: 11  state: 3003  wait: 1  next: 1000  dvx: 0  dvy: 0  centerx: 52  centery: 41  hit_a: 0  hit_d: 0  hit_j: 0
<frame_end>

<frame> 110 explosion
sound: data\089.wav  
   pic: 16  state: 18  wait: 1  next: 111  dvx: 0  dvy: 0  dvz: 0  centerx: 78  centery: 63  hit_a: 0  hit_d: 0  hit_j: 0
   itr:
      kind: 0  x: 23  y: 36  w: 112  h: 110  dvx: -12  dvy: -18  fall: 70  vrest: 300  bdefend: 16  injury: 75  zwidth: 37  
      effect: 21  
   itr_end:
<frame_end>

<frame> 111 explosion
sound: data\071.wav
   pic: 17  state: 18  wait: 1  next: 112  dvx: 0  dvy: 0  dvz: 0  centerx: 78  centery: 63  hit_a: 0  hit_d: 0  hit_j: 0
   itr:
      kind: 0  x: 20  y: 16  w: 122  h: 135  dvx: -12  dvy: -18  fall: 70  vrest: 300  bdefend: 16  injury: 75  zwidth: 37  
      effect: 21  
   itr_end:
<frame_end>

<frame> 112 explosion
   pic: 18  state: 18  wait: 1  next: 113  dvx: 0  dvy: 0  dvz: 0  centerx: 78  centery: 63  hit_a: 0  hit_d: 0  hit_j: 0
   itr:
      kind: 0  x: 19  y: 18  w: 127  h: 131  dvx: -12  dvy: -18  fall: 70  vrest: 300  bdefend: 16  injury: 75  zwidth: 37  
      effect: 21  
   itr_end:
<frame_end>

<frame> 113 explosion
   pic: 19  state: 18  wait: 1  next: 114  dvx: 0  dvy: 0  dvz: 0  centerx: 78  centery: 63 hit_a: 0  hit_d: 0  hit_j: 0
   itr:
      kind: 0  x: 7  y: 16  w: 146  h: 132  dvx: -12  dvy: -18  fall: 70  vrest: 300  bdefend: 16  injury: 75  zwidth: 37  
      effect: 21  
   itr_end:
<frame_end>

<frame> 114 explosion
   pic: 20  state: 18  wait: 1  next: 115  dvx: 0  dvy: 0  dvz: 0  centerx: 78  centery: 65  hit_a: 0  hit_d: 0  hit_j: 0
   itr:
      kind: 0  x: 13  y: 13  w: 137  h: 132  dvx: -12  dvy: -18  fall: 70  vrest: 300  bdefend: 16  injury: 75  zwidth: 37  
      effect: 21  
   itr_end:
<frame_end>

<frame> 115 explosion
   pic: 21  state: 18  wait: 1  next: 116  dvx: 0  dvy: 0  dvz: 0  centerx: 78  centery: 70  hit_a: 0  hit_d: 0  hit_j: 0
   itr:
      kind: 0  x: 7  y: 14  w: 145  h: 117  dvx: -12  dvy: -18  fall: 70  vrest: 300  bdefend: 16  injury: 75  zwidth: 37  
      effect: 21  
   itr_end:
<frame_end>

<frame> 116 explosion
   pic: 22  state: 18  wait: 1  next: 117  dvx: 0  dvy: 0  dvz: 0  centerx: 78  centery: 72  hit_a: 0  hit_d: 0  hit_j: 0
   itr:
      kind: 0  x: 15  y: 6  w: 128  h: 123  dvx: -12  dvy: -18  fall: 70  vrest: 300  bdefend: 16  injury: 75  zwidth: 37  
      effect: 21  
   itr_end:
<frame_end>

<frame> 117 explosion
   pic: 23  state: 18  wait: 1  next: 118  dvx: 0  dvy: 0  dvz: 0  centerx: 78  centery: 79  hit_a: 0  hit_d: 0  hit_j: 0
   itr:
      kind: 0  x: 15  y: 6  w: 128  h: 123  dvx: -12  dvy: -18  fall: 70  vrest: 300  bdefend: 16  injury: 75  zwidth: 37  
      effect: 21  
   itr_end:
<frame_end>

<frame> 118 explosion
   pic: 24  state: 18  wait: 1  next: 119  dvx: 0  dvy: 0  dvz: 0  centerx: 78  centery: 86  hit_a: 0  hit_d: 0  hit_j: 0
<frame_end>

<frame> 119 explosion
   pic: 25  state: 18  wait: 1  next: 120  dvx: 0  dvy: 0  dvz: 0  centerx: 78  centery: 82  hit_a: 0  hit_d: 0  hit_j: 0
<frame_end>

<frame> 120 explosion
   pic: 26  state: 18  wait: 1  next: 1000  dvx: 0  dvy: 0  dvz: 0  centerx: 76  centery: 77  hit_a: 0  hit_d: 0  hit_j: 0
<frame_end>

Here's code. Please help guys