function showTab(id)
{
var rimg=document.getElementById("rimage");//get reference to random image element
var rvid=document.getElementById("rvideo");//get reference to random image element

switch(id)
	{
case "rimage":

rimg.style.display="block";
rvid.style.display="none";
break;
case "rvideo" :

rimg.style.display="none";
rvid.style.display="block";
	}

	return false;
	}