文档介绍：转贴 <script> function test() {if(>50) {alert(" 不能超过 50个字符! "); (); return false; }}</script> <form name=a onsubmit="return test()"> <textarea name="b" cols="40" wrap="VIRTUAL" rows="6"></textarea> <input type="submit" name="Submit" value="check"> </form> <input onkeyup="value="/oblog/(/[^\u4E00-\u9FA5]/g,'')" >3." 只能是英文<script language=javascript> function onlyEng() {if(!(>=65&&<=90)) =false; }</script> <input onkeydown="onlyEng();"> <script language=javascript> function onlyNum() {if(!((>=48&&<=57)||(>=96&&even <=105))) //考虑小键盘上的数字键 =false; }</script> <input onkeydown="onlyNum();"> <input onkeyup="value="/oblog/(/[\W]/g,"'') "onbeforep aste="('text',('text').repl ace(/[^\d]/g,''))"> <SCRIPT LANGUAGE=javascript RUNAT=Server> function isEmail(strEmail) { if((/^\w+((-\w+)|(\.\w+))*\@[A-Za-z0-9]+((\.|-)[A-Za -z0-9]+)*\.[A-Za-z0-9]+$/) !=-1) return true; else alert("oh"); }</SCRIPT> <input type=text onblur=isEmail()> (这里屏蔽*** 和****) <script language=""> function test() {if(( ("***") ==0)||( ("****") ==0)){ alert(":)"); (); return false;} }</script> <form name=a onsubmit="return test()"> <input type=text name=b> <input type="submit" name="Submit" value="check"> </form> <FORM METHOD=POST ACTION=""> <input type="password" id="input1"> <input type="password" id="input2"> <input type="button" value="test" onclick="check()"> </FORM> <script> function check() { with(){ if(!=) {alert("false") =""; =""; }else [0].submit(); }}</script> 够了吧:) 屏蔽右键很酷 oncontextmenu="return false" ondragstart="return false" onselects tart="return false" 加在 body 表单项不能为空