var oldid=0;      
function showitm(nowid){      
	if(nowid!=oldid)
	{   
		myitm1[oldid].style.backgroundImage='url(Images/Skin/butto_left1.jpg)';      
		myitm2[oldid].style.backgroundImage='url(Images/Skin/butto_mid1.jpg)';       
		myitm3[oldid].style.backgroundImage='url(Images/Skin/butto_right1.jpg)';       
		myitm1[nowid].style.backgroundImage='url(Images/Skin/butto_left.jpg)';       
		myitm2[nowid].style.backgroundImage='url(Images/Skin/butto_mid.jpg)';        
		myitm3[nowid].style.backgroundImage='url(Images/Skin/butto_right.jpg)';        
		oldid=nowid; 
	}      
}