1. 长度限制 <script type="text/javascript"> function test() { if(document.a.b.value.length>50) { alert("不能超过50个字符！"); document.a.b.focus(); 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> 2. 只能是汉字 <input onkeyup="value="/oblog/value.replace(/[^u4E00-u9FA5]/g,'')"/> 3. 只能是英文 function onlyEng() { if(!(event.keyCode>=65&&event.keyCode<=90)) event.returnvalue=false; } </script> <input onkeydown="onlyEng();"/> 4. 只能是数字 <script type="text/javascript"> function onlyNum() { if(!((event.keyCode>=48&&event.keyCode<=57)||(event.keyCode>=96&&event.keyCode<=105))) //考虑小键盘上的数字键 event.returnvalue=false; } </script> <input onkeydown="onlyNum();"/> 5. 只能是英文字符和数字 <input onkeyup="value="/oblog/value.replace(/[W]/g,"'') "onbeforepaste="clipboardData.setData('text',clipboardData.getData('text').replace(/[^d]/g,''))"/> 6. 验证邮箱格式 <script type="text/javascript"> function isEmail(strEmail) { if (strEmail.search(/^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(this.value)/> 7. 屏蔽关键字(这里屏蔽***和****) <script type="text/javascript"> function test() { if((a.b.value.indexOf ("***") == 0)||(a.b.value.indexOf ("****") == 0)){ alert(":)"); a.b.focus(); return false; } } </script> <form name=a onsubmit="return test()"> <input type=text name=b/> <input type="submit" name="Submit" value="check"/> </form> 8. 两次输入密码是否相同 <from method=post action=""> <input type="password" id="input1"/> <input type="password" id="input2"/> <input type="button" value="test" onclick="check()"/> </from> <script type="text/javascript"> function check() { with(document.all){ if(input1.value!=input2.value) { alert("false") input1.value = ""; input2.value = ""; } else document.forms[0].submit(); } } </script> 路政管理系统应用： //非空验证 function checkoname(){ var casename= document.all['caseInfo.casename'].value; if(casename==""){ alert("案由不能为空！请输入执法机构"); casename.focus(); return false; } return true; } //机构简称非空验证 function checkcpunishbase(){ var cpunishbase=document.all['caseInfo.cpunishbase'].value; if(cpunishbase==""){ alert("处罚依据不能为空！请输入机构简称"); cpunishbase.focus(); return false; } return true; }