function showTips() {
	var contentDiv=document.getElementById("content");
	var tipsClass=contentDiv.getElementsByTagName("div");
	var aTag=contentDiv.getElementsByTagName("a");
	var imgTag=contentDiv.getElementsByTagName("img");
	for (i=0;i<imgTag.length;i++) {
		
	}
	//alert(imgTag.length);
	aTag[1].onmouseover =function(){
		tipsClass[1].style.display = "block";
	}
	aTag[1].onmouseout =function(){
		tipsClass[1].style.display = "none";
	}
	aTag[4].onmouseover =function(){
		tipsClass[7].style.display = "block";
	}
	aTag[4].onmouseout =function(){
		tipsClass[7].style.display = "none";
	}
	aTag[7].onmouseover =function(){
		tipsClass[13].style.display = "block";
	}
	aTag[7].onmouseout =function(){
		tipsClass[13].style.display = "none";
	}
	aTag[10].onmouseover =function(){
		tipsClass[19].style.display = "block";
	}
	aTag[10].onmouseout =function(){
		tipsClass[19].style.display = "none";
	}
	aTag[13].onmouseover =function(){
		tipsClass[25].style.display = "block";
	}
	aTag[13].onmouseout =function(){
		tipsClass[25].style.display = "none";
	}
}