function visible_hidden(id) {
	var element;
	element = document.getElementById(id);
	element.style.visibility=='hidden' ? element.style.visibility='visible' : element.style.visibility='hidden';
}
function visible_hidden_2(id) {
	var selects=document.getElementsByTagName("input");
	for(var i=0 ; i<selects.length ; i++)
	{
		if(selects[i].id.search(/^visible_/)>=0)
		{
			if(selects[i].id!="")
			{
			document.getElementById(selects[i].id).style.visibility= document.getElementById(selects[i].id).style.visibility== "hidden"?"visible":"hidden";
			}
		else
		{
			document.getElementById(selects[i].id).style.visibility= "hidden";   
		}
		
		}
	}
}