<script language="JavaScript">//设置焦点函数function focusElement(formName, elemName) {var elem = document.forms[formName].elements[elemName]; elem.focus( );elem.select( );}// 验证下拉框function isChosen(select){if (select.selectedIndex==0) {alert("请选择下拉单相应栏目.");focusElement(,);return false;} else {return true;}}//不为空函数function isNotEmpty(elem) {var str=elem.value;if(str==null || str.length==0) {alert("此项不能为空");focusElement(,);return false;} else {return true;}}// 验证是否是数字function isNumber(elem) {var str=elem.value;var oneDecimal=false;var oneChar=0;str=str.toString( );for (var i=0; i<str.length; i++) {oneChar=str.charAt(i).charCodeAt(0);// -if (oneChar==45) {if (i==0) {continue;} else {alert("Only the first character may be a minus sign.");setTimeout("focusElement('" + + "', '" + + "')", 0); return false;}}// 小数点if (oneChar==46) {if (!oneDecimal) {oneDecimal=true;continue;} else {alert("输入的数字只允许有一个小数点.");setTimeout("focusElement('" + + "', '" + + "')", 0); return false;}}// 数字只能在0和9之间if (oneChar<48 || oneChar > 57) {alert("此项只能输入数字.");setTimeout("focusElement('" + + "', '" + + "')", 0); return false;}}return true;}// 验证是否是数字电话function istel(elem) {var str=elem.value;var oneDecimal=false;var oneChar=0;str=str.toString( );for (var i=0; i<str.length; i++) {oneChar=str.charAt(i).charCodeAt(0);if(oneChar==45){continue;}if(oneChar<48 || oneChar > 57) {alert("此项只能输入数字和'-'号.");setTimeout("focusElement('" + + "', '" + + "')", 0); return false;}return true;}//验证输入数据的长度//邮编function isLenMatch(elem,lengthNum) {var str=elem.value;if (str.length != lengthNum) {alert("此项内容长度只能为"+lengthNum+"位.");setTimeout("focusElement('" + + "', '" + + "')", 0); return false;} else {return true;}}//邮件地址验证function isEMailAddr(elem) {var str = elem.value;var re = /^[\w-]+(\.[\w-]+)*@([\w-]+\.)+[a-zA-Z]{2,7}$/;if (!str.match(re)) {alert("您输入的不是有效的e-mail地址.");setTimeout("focusElement('" + + "', '" + + "')", 0); return false;} else {return true;}}//单选按钮验证function isValidRadio(radio) {var valid=false;for (var i=0; i<radio.length; i++) {if (radio.checked) {return true;}}alert("单选按钮未选中.");radio[0].focus();//setTimeout("focusElement('" + radio[0] + "', '" + radio[0].name + "')", 0); focusElement(radio[0],radio[0].name);return false;}</script><script language="JavaScript">function validateForm(form) {if (isNotEmpty(1) && isNotEmpty(2)) {;}else{return false;}</script><title>JS验证程序Sample</title></head><body><form method="GET" action="index.htm" name="sampleForm" onsubmit="return validateForm(this)"><p>姓名:<input type="text" size="30" name="name1" id="name1" /></body></html>表单验证很有用长度限制<script>function test(){if(document.a.b.value.length>50){alert("不能超过50个字符！");document.a.b.focus();return false;}}</script><form name=a onsubmit="return test()"><textarea name="b" cols="40" wrap="VIRTUAL" rows="6"></textarea><input type="submit" name="Submit" value="check"></form>2 只能是汉字<input onkeyup="value=value.replace(/[^\u4E00-\u9FA5]/g,'')">3 只能是英文<script language=javascript>function onlyEng(){if(!(event.keyCode>=65&&event.keyCode<=90))event.returnvalue=false;}</script><input onkeydown="onlyEng();">4 只能是数字<script language=javascript>function onlyNum(){if(!((event.keyCode>=48&&event.keyCode<=57)||(event.keyCode>=96&&event.keyCode<=105) ))//考虑小键盘上的数字键event.returnvalue=false;}</script><input onkeydown="onlyNum();">5 只能是英文字符和数字<input onkeyup="value=value.replace(/[\W]/g,'') "onbeforepaste="clipboardData.setData('text',clipboardData.getData('text').replace(/[^\d]/g,''))">6 验证油箱格式<SCRIPT LANGUAGE=javascript RUNAT=Server>function isEmail(strEmail) {if(strEmail.search(/^\w+((-\w+)|(\.\w+))*\@[A-Za-z0-9]+((\.|-)[A-Za-z0-9]+)*\.[A-Za-z0-9]+$/) != -1)return true;elsealert("oh");}</SCRIPT><input type=text onblur=isEmail(this.value)>7 屏蔽关键字(这里屏蔽sex和****)<script language="javascript1.2">function test() {if((a.b.value.indexOf ("sex") == 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<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(document.all){if(input1.value!=input2.value){alert("false")input1.value = "";input2.value = "";}else document.forms[0].submit();}}</script>网页表单的javascript集成验证方法举例原理：表单验证无非是要对要收集每一条信息进行验证，也就是要写一个名为frmValid的javascript函数，在其中执行如下操作：...if (待验证条目不符合条件){alert('出错了!');待验证条目.focus();return false;}...// all rightreturn true;当然，<form ... onsubmit='return frmValid()'>必须包含在HTML代码中。