js简单表单验证

//验证用户名

function checkName(){
	var name = document.getElementById("name").value;
	if(name == null || name == ""){
		alert("用户名不能为空");
		return false;
	}else{
		return true;
	}
}

//验证密码

function checkPassword1(){
	var password = document.getElementById("password1").value;
	if(password == null || password == ""){
		alert("密码不能为空");
		return false;
	}else if(password.length < 6 || password.length > 16){
		alert("密码必须在6到16个字符内");
		return false;
	}else{
		return true;
	}
}

//验证密码是否相等

function checkPassword2(){
	var password1 = document.getElementById("password1").value;
	var password2 = document.getElementById("password2").value;
	if(password2 == null || password2 == ""){
		alert("不能为空");
		 return false;
	}else if(password1 != password2){
		alert("两次输入密码不一致");
		return false;
	}else{
		return true;
	}
}

//判断电话号码
//number:要判断的文本框,resultStr:返回的消息存放处

function checkNumber(number,returnStr){
	var num = document.getElementById(number).value;
	var re = /^[0-9,]*$/;		//验证只能为数字的正则表达式
	if(!re.test(num)){
		document.getElementById(returnStr).innerHTML="<font color='red'>电话只能输入数字</font>";
		document.getElementById(number).focus();		//设置文本框得到光标
		return false;
	}else if(num.length < 8 || num.length > 12){//如果字符的长度小于0，或者大于11
		document.getElementById(returnStr).innerHTML="<font color='red'>电话不能为空，并且不能超过8-12位字符</font>";
		document.getElementById(number).focus();		//设置文本框得到光标
		return false;
	}else {
		document.getElementById(returnStr).innerHTML="<font color='green'>填写合格</font>";
		return true;
	}
}

//验证邮箱

function checkEmail(e_mail,returnStr){
	var email = document.getElementById(e_mail).value;
	var str = /^([a-zA-Z0-9_-])+@([a-zA-Z0-9_-])+(\.[a-zA-Z0-9_-])+/;
 	if(!str.test(email)){
 		document.getElementById(returnStr).innerHTML="<font color='red'>邮箱格式不正确，格式如：[e-mail]</font>";
 		return false;
 	}else{
 		document.getElementById(returnStr).innerHTML="<font color='green'>填写合格</font>";
        return true;
 	}
}

//表单验证

function formCheck(){
	if(checkName() && checkPassword1() && checkPassword2() && checkAge() &&checkEmail()){
		return true;
	}else{
		return true;
	}
}