function butOver(el){
	path = el.src.split('/');
	file = path[path.length-1];
	file_parts = file.split('.');
	if(file_parts[0].substr(file_parts[0].length - 2, file_parts[0].length)  == "_o"){ 
		return;
	}
	out_src = el.src;
	src_parts = el.src.split('.gif');
	if (src_parts.length==2)
	{
	over_src = src_parts[0]+"_o"+".gif";
	}
	else
	{	
			src_parts = el.src.split('.jpg');
			over_src = src_parts[0]+"_o"+".jpg";
	}
	
	el.src = over_src;el.onmouseout = function(){this.src = out_src;}
}