为当前元素弹出一个提示信息，需要当前元素的ID和要弹出的字符串。

pmt.js

function pmt(eleId, pmt) {
  if( document.getElementById("pmt") != null ){
		return ;
	}
	var pmtLabel = document.createElement("div");
	pmtLabel.id = "pmt";
	pmtLabel.innerHTML = pmt;

	var pmtTriangle = document.createElement("div");
	pmtTriangle.id = "pmtTriangle";

	
	document.getElementsByTagName("body").item(0).appendChild(pmtTriangle);
	document.getElementsByTagName("body").item(0).appendChild(pmtLabel);
	
	var element = document.getElementById(eleId);
	
	var putWidth = document.getElementById("pmt").offsetWidth;
	var pmtTriangleWidth = document.getElementById("pmtTriangle").offsetWidth;
	var bodyScolY = document.body.scrollTop == 0 ? document.documentElement.scrollTop : document.body.scrollTop;
	var bodyScolX = document.body.scrollLeft == 0 ? document.documentElement.scrollLeft : document.body.scrollLeft;
	var eleY = element.getBoundingClientRect().top;
	var eleX = element.getBoundingClientRect().left;
	var eleHeight = element.offsetHeight;
	var eleWidth = element.offsetWidth;
	var putY = eleY + eleHeight + bodyScolY;
	var putX = eleX + ( eleWidth / 2 ) - (putWidth / 2) + bodyScolX;
	var pmtTriangleX = eleX + ( eleWidth / 2 ) - (pmtTriangleWidth / 2) + bodyScolX;

	document.getElementById("pmt").style.top = putY + 10 + "px";
	document.getElementById("pmt").style.left = putX + "px";

	document.getElementById("pmtTriangle").style.top = putY + 1 + "px";
	document.getElementById("pmtTriangle").style.left = pmtTriangleX + "px";

	setTimeout("if (document.getElementById('pmt') != null) { document.getElementById('pmt').style.display = 'block'; document.getElementById('pmtTriangle').style.display = 'block'; }", 1000);
	pmtLabel.style.display = "none";
	pmtTriangle.style.display = "none";
}
function erasePmt(){
	document.getElementsByTagName("body").item(0).removeChild(document.getElementById("pmt"));
	document.getElementsByTagName("body").item(0).removeChild(document.getElementById("pmtTriangle"));
}