51help TIY
码：
<html> <head> <script type="text/javascript"> function validate() { var at=document.getElementById("email").value.indexOf("@") var age=document.getElementById("age").value var fname=document.getElementById("fname").value submitOK="true" if (fname.length>10) { alert("于 10 个字符。") submitOK="false" } if (isNaN(age)||age<1||age>100) { alert(" 1 与 100 。") submitOK="false" } if (at==-1) { alert("址。") submitOK="false" } if (submitOK=="false") { return false } } </script> </head> <body> <form action="http://www.51help.tk/example/hdom/hdom_submitpage.html" onsubmit="return validate()"> 10 <input type="text" id="fname" size="20"><br /> 年龄（从 1 到 100）：<input type="text" id="age" size="20"><br /> <input type="text" id="email" size="20"><br /> <br /> <input type="submit" value="提交"> </form> </body> </html>
查看结果: