<!DOCTYPE html> <html> <head> <meta charset="UTF-8"> <title></title> </head> <body> <form name="frm" method="post"> <table> <tr><td>用户名:</td><td><input type="text" name="" id="usernameId" value="" /></td><td><span id="userSpanId"></span></td></tr> <tr><td>密码:</td><td><input type="password" name="" id="pwdId" value="" /></td><td><span id="pwdSpanId"></span></td></tr> <tr><td>确认密码:</td><td><input type="password" name="" id="confPwdId" value="" /></td><td><span id="confPwdSpanId"></span></td></tr> <tr><td><input type="button" onclick="check()" value="注册" /></td></tr> </table> </form> <script type="text/javascript"> function check(){ var result1=checkUserName(); var result2=checkPwd(); var result3=checkTwoPwd(); if(result1 && result2 && result3){ document.frm.action="RegisterServlet"; document.frm.submit(); } } function checkUserName(){ var uname=document.getElementById("usernameId"); var span=document.getElementById("userSpanId"); if(uname.value.trim().length==0){ span.innerHTML="<font color='red'>用户名不能为空啊!</font>"; return false; }else{ span.innerHTML="√"; return true; } } function checkPwd(){ var pwd=document.getElementById("pwdId"); var span=document.getElementById("pwdSpanId"); if(pwd.value.trim().length==0){ span.innerHTML="密码不能为空"; return false; }else{ span.innerHTML="√"; return true; } } function checkTwoPwd(){ var pwd=document.getElementById("pwdId"); var confPwd=document.getElementById("confPwdId"); var pwdspan=document.getElementById("pwdSpanId"); var confpwdSpan=document.getElementById("confPwdSpanId"); if(pwd.value==confPwd.value){ return true; }else{ confpwdSpan.innerHTML="两次密码不一致"; return false; } } </script> </body> </html>