Javascript CheckForm

[The1corrupted]

I have a slight dilema on my hands. I want to check this form before submitting it, and making sure everything's filled out. I know there's a way to do it in javascript, but haven't found any methods to do so.

<script language=\"javascript\" type=\"text/javascript\">
    function checkform(user, password, email) {
        if (user==NULL) {
            alert(\"Check your username!\")
            }
        }
    <script>
 
<form method=\"post\" action=\"".$_SERVER['PHP_SELF']."\">
                    <table style=\"border-style:none;\" align=\"center\">
                        <tr>
                            <td>
                                Ruler Name:
                            </td>
                            <td>
                                <input type=\"text\" name=\"user\" length=\"20\">
                            </td>
                        </tr>
                        <tr>
                            <td>
                                E-mail Address:
                            </td>
                            <td>
                                <input type=\"text\" name=\"email\" length=\"20\">
                            </td>
                        </tr>
                        <tr>
                            <td>
                                Password:
                            </td>
                            <td>
                                <input type=\"password\" name=\"password\" length=\"20\">
                            </td>
                        </tr>
                        <tr>
                            <td>
                                Empire Name:
                            </td>
                            <td>
                                <input type=\"text\" name=\"empirename\" length=\"20\">
                            </td>
                        </tr>
                        <tr>
                            <td>
                                Economic System:
                            </td>
                            <td>
                                <select name=\"economic\">
                                    <option selected>--------</option>
                                    <option>Capitalist</option>
                                    <option>Facist</option>
                                    <option>Laissez-faire</option>
                                    <option>Natural</option>
                                    <option>Socialist</option>
                                </select>
                            </td>
 
                            <td>
                                <input type=\"button\" value=\"Submit\" onClick=\"checkform()\">
                            </td>
                        </tr>
                    </table>
                </form>

[The1corrupted]

Nevermind the onClick function, I'll parse it with an onMouseOver, but I still need help to display an alert message telling you which fields are blank. Preferrably, I would like the errors all to show up in one alert.

[gits]

hi ...

have a look at the following example that you may use onsubmit of the form you want to check:

function check_form(f) {
    var errors = [];
    var val    = true;
    var tboxes = f.getElementsByTagName('input');
 
    for (var i = 0; i < tboxes.length; i++) {
        var t = tboxes[i];
 
        if (t.value === '') {
            errors.push(t.name);
        }
    }
 
    if (errors.length > 0) {
        alert('Please fill out the following fields:\n' + errors.join('\n'));
        val = false;
    }
 
    return val;
}
 

call it the following way:

[HTML]<form name="myform" onsubmit="check_form(this);">
[/HTML]
in your html ...

kind regards