function showPlayBtn(obj){
//	if(event.srcElement != this) return;
	var thumbSize = [obj.offsetWidth, obj.offsetHeight],btnSize = [25,25];
	var oBtn = document.getElementById("play-btn");
	var absPos = obj.getBoundingClientRect();
	var scrollX = Math.max(document.documentElement.scrollLeft, document.body.scrollLeft);
	var scrollY = Math.max(document.documentElement.scrollTop, document.body.scrollTop);
	var ua = navigator.userAgent;
	
	if(!oBtn){
		oBtn = document.createElement("div");
		oBtn.id = oBtn.className = "play-btn";
		oBtn.onmouseover = function(){
			oBtn.style.display = "block";
			}
		document.body.appendChild(oBtn);
		document.body.appendChild(oBtn);
	}
	oBtn.onclick = function(){
		open(obj.parentNode.href, "", "");
		}
	oBtn.style.display = "block";
	oBtn.style.left = (absPos.left + scrollX + (thumbSize[0]-btnSize[0])/2) + "px";
	oBtn.style.top = (absPos.top + scrollY + (thumbSize[1]-btnSize[1])/2) + "px";
}
function hidePlayBtn(){
	var oBtn = document.getElementById("play-btn");
	if(oBtn) oBtn.style.display = "none";
}