This might help, its my first attempt at working with C script and compiled from Many members pointers plus George and AUM.

Code:

---

  ////////////////////////////////////////////////////////////////////////////////
//1st person shooter perspective

var player_distance; // moves the player
var jumping = 0;
var vecFrom[3]; 
var vecTo[3]; 

////////////////////////////////////////////////////////////////////////////////

define health = skill18; // just another name for skill18

///////////////////////////////////////////////////////////////////////////////

function player_event();
function player_jumps();

///////////////////////////////////////////////////////////////////////////////

action player_me // attached to the player 
{ 
     my.fat = on;
     my.narrow = on;
     c_setminmax(my);

     player = my; // I'm the player 
	  my.invisible = on;
     my.enable_scan = on;
     my.enable_shoot = on;
     my.enable_impact = on;

     player.health = 200; // and I have 100 health points 

   		while (my.health > 0)
			{
				vec_set (camera.pos, my.pos);
				camera.x = my.x;
				camera.y = my.y;
				camera.z = my.z+30 ;
				camera.tilt += 15 * mouse_force.y * time;
				camera.pan -= 15 * mouse_force.x * time;
				my.pan = camera.pan;	
			//	my.tilt = camera.tilt;

				player_distance.x = 30 * (key_w - key_s) * time; // moves forward / backward with W / S
				player_distance.y = 30 * (key_a - key_d) * time;
				player_distance.z = 30 * (key_space - key_c) * time;
	

				if (key_shift ==1 && key_w==1 )
					{
						player_distance.x += 65 *  time;
					}

				if (jumping == 0)
					{
						vec_set (temp, my.x); 
						temp.z -= 10000; 
						trace_mode = ignore_me + ignore_passable + use_box+activate_sonar; 		
						my.skill30 = trace (my.x, temp);
						if(result <= 0 ) 
					{ 
						//place player on ground 
						vec_set(VecFrom,my.x); 
						vec_set(VecTo,my.x);
						VecTo.z -= 30* time; // place player on floor 
						my.z -= c_trace(VecFrom.x,VecTo.x,ignore_me+ignore_sprites+ignore_passable+ignore_passents+use_box); 
						my.z += 1; 
					}
				
				if (my.skill30 < 20) // fall on the ground when closer than 50 quants to the surface
					{
		      		player_distance.z = -my.skill30; 
					}
				else // way up in the air?
					{
						player_distance.z -= 30 * time; // then decrease player's z slowly
					} 
						my.skill30 = -trace (my.x, temp);
											
					}
				
				if ((key_space == 1) && (jumping == 0)) // space to jump 
        			{ 
						player_jumps();
        			}
	
         			c_move(my,player_distance,nullvector,ignore_passable  + glide); 

		          	wait (1);       
     		} 
 
  
}}	


////////////////////////////////////////////////////////////////////////

function player_jumps()
{
	proc_kill(4);
	my.skill20 = 0;
	jumping = 1;
	while (my.skill20 < 30) //'hang' duration
	{
	      ent_animate("jump", my.skill20); 
	      my.skill20 += 3 * time; // "jump" animation speed 
	
      	if (my.skill20 < 30) 
	      { 	
      	    	player_distance.z += 0.1 * time; 
	      } 
		else
		{
      	    	player_distance.z -= 0.1 * time; 
		}
		wait (1);
	}
	jumping = 0;
}

////////////////////////////////////////////////////////////////////////////////////


function player_event()
{
	while (player == null) 
	{
		wait (1);
	}
	if (my.health > 0)
	{
		my.health -= 10;

}
}


//////////////////////////////////////////////////////////////////////////////

action poly 
{ 
my.polygon = on; 
} //attach to model ground entities.

---

Bit of a hash but it worked fine at the time.