我的表单验证功能出了什么问题？

Question

I have a simple form that asks for Name, Email, Phone Number, Age and Income. When I hit submit, the validateForm function is supposed to check for errors and if there are any errors the textbox will be red and there will be a red error message display under the form. The function doesn't seem to be working at all and I'm not sure why. This is my form and script. I tried setting the submit button to have an onclick event to call the function but that didn't work either.

<script>
function validateForm() {



    if (document.forms.formValidation.Name.value == "") {

        document.getElementById("error").style.display = "inline";
        document.forms.formValidation.getElementById("name").style.backgroundColor = "red";

        return false;
    }
    if (document.forms.formValidation.email.value == "") {
        document.getElementById("error").style.display = "inline";
        document.forms.formValidation.email.style.backgroundColor = "red";
    }
    var phoneNo = /^\d{10}$/;
    if (document.forms.formValidation.number.value.match(phoneNo)) {
        return true;
    }
    else {
        document.getElementById("error").style.display = "inline";
        document.forms.formValidation.number.style.backgroundColor = "red";
        return false;
    }

    var emailVal = document.formValidation.email.value;
    ampersandPos = emailVal.indexOf("@");
    dotPos = emailVal.lastIndexOf(".");

    if (amersandPos < 1 || (dotPos - amersandPos < 2)) {
        alert("Please enter a valid email address.");
        document.getElementById("error").style.display = "inline";
        return false;
    }
    return true;

    var len = age.length;
    for (var i = 0; i < len; i++) {
        if (document.forms.formValidation.age[i].checked)
        {
            return true;
        }
        else {
            document.getElementById("error").style.display = "inline";
            return false;
        }
    }




}

</script>

<form name="formValidation" onsubmit="return validateForm()">
                    <table cellspacing="2" cellpadding="2" border="1">
                        <tr>
                            <td align="right">First and Last Name: </td>
                            <td align="left"><input type="text" id="name" name="Name" ></td>
                        </tr>
                        <tr>
                            <td align="right">Email: </td>
                            <td align="left"><input type="text" id="email" name="email" ></td>
                        </tr>
                        <tr>
                            <td align="right">Phone Number: </td>
                            <td align="left"><input type="text" name="number" /></td>
                        </tr>
                        <tr>
                            <td align="right">Age:</td>
                            <td class="rad"><input type="radio" name="age" value="minor">Under 18</td>
                            <td class="rad"><input type="radio" name="age" value="adult">18-64</td>
                            <td class="rad"><input type="radio" name="age" value="senior">65+</td>
                        </tr>
                        <tr>
                            <td align="right">Income:</td>
                            <td>
                                <select>
                                    <option value="underFifty">Under $50,000</option>
                                    <option value="fiftyToHundred">$50,000 - $100,000</option>
                                    <option value="overHundred">Over $100,000</option>
                                </select>
                            </td>
                        </tr>

                    </table>
                    <input type="submit" value="Submit">                
                    </form>
                    <div id="error">
                        <p>Required fields are missing!</p>
                    </div>

Answer 1

You are missing a closing parenthesis on this line:

if (amersandPos < 1 || (dotPos - amersandPos < 2)

Also, this line is not valid:

document.formValidation.email.style.background-color = "red";

Because background-color is not a valid identifier name.

Here's a fiddle with these and the one issue in the comment fixed: https://jsfiddle.net/0zyv3g98/

Answer 2

You have mistakes in you js. you cannot use document.formValidation.name or something like that. the correct syntax is `document.forms.formValidation. Correction all your code and it will work.

      if (document.forms.formValidation.Name.value == "") {

        document.forms.formValidation.getElementById("error").style.display = "inline";
        document.forms.formValidation.getElementById("name").style.backgroundColor = "red";

        //return false;
    }
    if (document.forms.formValidation.email.value == "") {
        document.forms.formValidation.getElementById("error").style.display = "inline";
        document.forms.formValidation.email.style.backgroundColor = "red";
    }

    var emailVal = document.forms.formValidation.email.value;
    ampersandPos = emailVal.indexOf("@");
    dotPos = emailVal.lastIndexOf(".");

    if (amersandPos < 1 || (dotPos - amersandPos < 2)
    {
        alert("Please enter a valid email address.");
        document.forms.formValidation.getElementById("error").style.display = "inline";
        return false;
    }
    return true;