Form shouldn't be submitted if Check box is not selected [duplicate]

This question already has answers here: Closed 11 years ago.

Possible Duplicate:

Recommendation for javascript form validation library

In my HTML page there is a radio button, if that radio button is selected it will enable a div containing a textbox.

I need some validation here. If the checkbox is selected and textbox is empty then the submit button should not work and it should remain on the same page.

How can i implement this?

edited the code so that it will work now.

How can I implement this in Play! Framework? This is a part of my code

<div id="ask-poll">
    <form name="myform" action="@{Application.askquestion()}" onsubmit="return validateThisForm();">
    <div class="wf-group">
      <p><label for="questionText"><h3>Who d开发者_开发知识库o you want to ask for their opinion?</h3></label></p>

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While this isnt a coded answer, there are a number of form validation javascript examples (hence Im not going to insult you by posting a bunch of links to them) where you can see how they use javascript to test if all the required elements are completed, eg, various "required" textboxes, a "have you read this" checkbox etc. You then implement this as part of the submit "onclick" and if its not valid you return "false" this prevents the form being submitted.

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This has been taken from @danyolgiax's link

function theChecker()
{ 
if(document.theForm.theCheck.checked==false)
{
document.theForm.theButton.disabled=true;
}
else
{
document.theForm.theButton.disabled=false;
}
}
</script>

---

In case You want to use jquery here is a sample code :

$(document).ready(function()
{
    $("#somediv").hide(); //hide div
    $('input[type=submit]').attr("disabled","disabled"); //disable submit button
    function checkAll()  //prepare function for disabling / enabling submit button
    {
        if($('input[type=text]').val() == '')
        {
            $('input[type=submit]').attr("disabled","disabled");
        }
        else
        {
            $('input[type=submit]').removeAttr('disabled');
        }
    }
    $('input[type=text]').bind('mouseenter mouseleave focus blur keypress', function() {
        checkAll();
    });  //bind function for text input, checking if its empty or not and calling checkAll() function

    $('input:radio')click(function() // bind function for radio that will show div after clicking
    {
        $("#somediv").show();
    });
}