<!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"> <head> <title></title> <script type="text/javascript" defer="defer"> document.getElementById("form1").onsubmit = function (e) { alert("Submit prevented"); e.preventDefault(); //return false; } </script> </head> <body> <label>aaa</label> <form id="form1" action="Default.aspx" > <input type="submit" value="Submit" /> </form> </body> </html>
e.preventDefault()和return false;都可以阻止提交，之前的语句可以验证form里内容是否合法