tick_img = new Image (16,16);
tick_img.src= "/ye.gif";

tick_black_img = new Image(16,16);
tick_black_img.src = "/ye_black.gif";


function checkTick(pref,prefImg,id)
{
	el = document.getElementById(pref+id);
	img = document.getElementById(prefImg+id);
	if (el.value == id) {
		//uncheck this
		el.value = 0;
		img.src = tick_black_img.src;
	} else {
		//check this
		el.value = id;
		img.src = tick_img.src;
	}
	return false;
}