<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8" />
<title>form表单验证</title>
<script type="text/javascript">
// 1.当用户名获得焦点时, 调用函数
function username_focus(){
var obj = document.getElementById('username_result');
obj.style.color = '#666';
obj.innerHTML = '请输入你的用户名！';
}
// 定义函数：当失去焦时验证用户名
function username_blur(){
var obj = document.getElementById('username_result');
var value = document.form1.username.value;
if( value == '' ){
obj.style.color = '#f00';
obj.innerHTML = '用户名不能为空';
return false;
} else if( value.length < 5 || value.length > 20 ){
obj.style.color = '#f00';
obj.innerHTML = '用户名长度应介于5-20之间';
return false;
} else {
obj.style.color = '#090';
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8" />
<title>form表单验证</title>
<script type="text/javascript">
// 1.当用户名获得焦点时, 调用函数
function username_focus(){
var obj = document.getElementById('username_result');
obj.style.color = '#666';
obj.innerHTML = '请输入你的用户名！';
}
// 定义函数：当失去焦时验证用户名
function username_blur(){
var obj = document.getElementById('username_result');
var value = document.form1.username.value;
if( value == '' ){
obj.style.color = '#f00';
obj.innerHTML = '用户名不能为空';
return false;
} else if( value.length < 5 || value.length > 20 ){
obj.style.color = '#f00';
obj.innerHTML = '用户名长度应介于5-20之间';
return false;
} else {
obj.style.color = '#090';
obj.innerHTML = '用户名合法';
return true;
}
}
// 2.当密码获得焦点时, 调用函数
function password_focus(){
var obj = document.getElementById('password_result');
obj.style.color = '#666';
obj.innerHTML = '请输入你的密码';
}
// 定义函数：当失去焦点时验证密码
function password_blur(){
var obj = document.getElementById('password_result');
var value = document.form1.password.value;
if( value.length == 0 ){
obj.style.color = '#f00';
obj.innerHTML = '密码不能为空';
return false;
} else if( value.length < 5 || value.length > 20 ){
obj.style.color = '#f00';
obj.innerHTML = '密码长度应介于5-20之间的字符';
return false;
} else {
obj.style.color = '#090';
obj.innerHTML = '密码合法！';
return true;
}
}
// 点击'提交'按钮时, 来一个统一的验证
function checkForm(){
// 将用户失去焦点的验证的结果, 赋给一个变量
var userName = username_blur();
var passWord = password_blur();
if( userName && passWord ){
alert('验证通过');
return true;
} else {
alert('验证失败');
return false;
}
}
// 函数初始化
function init(){
document.form1.username.focus();
}
</script>
</head>
<body onload="init()">
<form name="form1" method="get" action="login.php" onsubmit="return checkForm()">
<table width="500" border="0" align="center">
<tr>
<td align="right"><b>用户名：</b></td>
<td><input type="text" name="username" onfocus="username_focus()" onblur="username_blur()" /></td>
<td width="250"><span id="username_result"></span></td>
</tr>
<tr>
<td align="right"><b>密码：</b></td>
<td><input type="password" name="password" onfocus="password_focus()" onblur="password_blur()" /></td>
<td><span id="password_result"></span></td>
</tr>
<tr>
<td align="right"> </td>
<td colspan="2"><input type="submit" value="提交表单" /></td>
</tr>
</table>
</form>
</body>
</html>
obj.innerHTML = '用户名合法'; return true; } } // 2.当密码获得焦点时, 调用函数 function password_focus(){ var obj = document.getElementById('password_result'); obj.style.color = '#666'; obj.innerHTML = '请输入你的密码'; } // 定义函数：当失去焦点时验证密码 function password_blur(){ var obj = document.getElementById('password_result'); var value = document.form1.password.value; if( value.length == 0 ){ obj.style.color = '#f00'; obj.innerHTML = '密码不能为空'; return false; } else if( value.length < 5 || value.length > 20 ){ obj.style.color = '#f00'; obj.innerHTML = '密码长度应介于5-20之间的字符'; return false; } else { obj.style.color = '#090'; obj.innerHTML = '密码合法！'; return true; } } // 点击'提交'按钮时, 来一个统一的验证 function checkForm(){ // 将用户失去焦点的验证的结果, 赋给一个变量 var userName = username_blur(); var passWord = password_blur(); if( userName && passWord ){ alert('验证通过'); return true; } else { alert('验证失败'); return false; } } // 函数初始化 function init(){ document.form1.username.focus(); } </script> </head> <body onload="init()"> <form name="form1" method="get" action="login.php" onsubmit="return checkForm()"> <table width="500" border="0" align="center"> <tr> <td align="right"><b>用户名：</b></td> <td><input type="text" name="username" onfocus="username_focus()" onblur="username_blur()" /></td> <td width="250"><span id="username_result"></span></td> </tr> <tr> <td align="right"><b>密码：</b></td> <td><input type="password" name="password" onfocus="password_focus()" onblur="password_blur()" /></td> <td><span id="password_result"></span></td> </tr> <tr> <td align="right"> </td> <td colspan="2"><input type="submit" value="提交表单" /></td> </tr> </table> </form> </body> </html>