JavaScript 表单

JavaScript 实例

function validateForm() {
    var x = document.forms["myForm"]["fname"].value;
    if (x == null || x == "") {
        alert("需要输入名字。");
        return false;
    }
}

HTML 表单实例

<form name="myForm" action="demo_form.php" onsubmit="return validateForm()" method="post">
名字: <input type="text" name="fname">
<input type="submit" value="提交">
</form>

function myFunction() {
    var x;
    var text = "输入正确";

    //Get the value of input field with id="numb"
    x = document.getElementById("numb").value;

    // If x is Not a Number, or x is less than one, or x is grather than 10 then
    if (isNaN(x) || x < 1 || x > 10) {
        text = "输入错误";
    }
    document.getElementById("demo").innerHTML = text;
}


请输入 1 到 10 之间的数字：


提交

实例

<form action="demo_form.php" method="post">
  <input type="text" name="fname" required="required">
  <input type="submit" value="提交">
</form>