function tab(){
	if (document.getElementById("444").style.display='block'){	
		document.getElementById("666").style.display='none';
		document.images["a"].src="images/key-a.jpg";// key active image	
	}
	if (document.getElementById("666").style.display='none'){
		document.images["b"].src="images/desc.jpg"; //desc unactive image
	}
}
function tab1(){
	if (document.getElementById("666").style.display='block'){
		document.getElementById("444").style.display='none';
		document.images["b"].src="images/desc-a.jpg"; //desc active image
	}
	if (document.getElementById("444").style.display='none'){
		document.images["a"].src="images/key.jpg"; //key unactive image
	}
}