JavaScript鼠标点到文本框时的提示信息
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"><head> <title></title> <style type="text/css"> *{ margin:0px;padding:0px;font-size:12px; } input{ width:100px;height:20px;border:1px solid #ccc; } </style></head><body><script language="javascript">function tips(id,str){var l=document.getElementById(id).offsetLeft;alert(document.getElementById(id).offsetTop); alert(document.getElementById(id).clientHeight);var t=document.getElementById(id).offsetTop+document.getElementById(id).clientHeight+5;document.getElementById("tips").innerHTML="提示："+str;document.getElementById("tips").style.left=l+"px";document.getElementById("tips").style.top=t+"px";document.getElementById("tips").style.display="";}function outtips(){ document.getElementById("tips").style.display='none';}</script><div id="tips" style="position:absolute;border:1px solid #ccc;padding:0px 3px;color:#f00;display:none;height:20px;line-height:20px;background:#fcfcfc"></div><br />姓名：<input type="text" id="username" onfocus="tips('username','姓名长度最多16个字符')" onblur="outtips()" /><br />密码：<input type="password" id="password" onfocus="tips('password','密码长度必须在3-18位之间')" onblur="outtips()" /></body></html>