function toggleVisibility(divid){
		var thediv = document.getElementById(divid);
		for (var x = 1; x <= 4; x++)
		{
			var thed = document.getElementById('humanv' + x);
			if (thed != thediv) {
				if (thed.style.visibility == 'visible') {
					thed.style.visibility='hidden';
				}
			}
		}
		
		if (thediv.style.visibility=='hidden' ){
			thediv.style.visibility='visible';
		}
		else {
			thediv.style.visibility='hidden';
		}
	}
	
	if (document.images) {
	man1=new Image(21,21); man1.src = "assets/man1.gif";
	man2=new Image(21,21); man2.src = "assets/man2.gif";
	woman1=new Image(21,21); woman1.src = "assets/woman1.gif";
	woman2=new Image(21,21); woman2.src = "assets/woman2.gif";
	}
	function SwapImg(imgnum, imgsrc) {
    	if (document.images) {
			document.images['but'+imgnum].src=imgsrc.src;
			return true;
		}
	}