img0_on = new Image(100,50); 
img0_on.src="gfx/option1_on.jpg"; 
img0_off = new Image(100,50); 
img0_off.src="gfx/option1_off.jpg"; 

img1_on = new Image(100,50); 
img1_on.src="gfx/option2_on.jpg"; 
img1_off = new Image(100,50); 
img1_off.src="gfx/option2_off.jpg"; 





function over_image(parm_name) 
{ 
document[parm_name].src = eval(parm_name + "_on.src"); 
} 
function off_image(parm_name) 
{ 
document[parm_name].src = eval(parm_name + "_off.src"); 
}