Jquery stop form submit unless checkbox selected

I've got this code, but it doesn't seem to return true. The alert always shows up. Any thoughts (without needing to create a var in which to store that a checkbox has been selected as that just seems a bit hacky).

Thanks.

$("#form").submit(function(e) {
    $('input[type=checkbox]').each(function () {
        if(this.checked){
            return true;
        }
    });
    alert("Please select at least one to upgrade.");
    return f开发者_JS百科alse;
});

You don't need to do the loop to determine if a checkbox is checked. The :checked selector filters out all that are not checked. Then you can use $.length to get a count of the checked inputs.

$("#form").submit(function(e) {
    if(!$('input[type=checkbox]:checked').length) {
        alert("Please select at least one to upgrade.");

        //stop the form from submitting
        return false;
    }

    return true;
});

Additionally, using your approach, a small change should make this work

$("#form").submit(function(e) {
    $('input[type=checkbox]').each(function () {
        if($(this).is(':checked')){
            return true;
        }
    });
    alert("Please select at least one to upgrade.");
    return false;
});

I think you may be simply missing the $() around this

Just to point out, you're using the id reference #form. Did you mean to just refer to all forms, or does the form have the id form?

Example of checking the number of checboxes checked...

<script>

    function countChecked() {
      var n = $("input:checked").length;
      $("div").text(n + (n <= 1 ? " is" : " are") + " checked!");
    }
    countChecked();
    $(":checkbox").click(countChecked);

</script>

Above "$("input:checked")" returns the array of checked items... You could check the "length" of this array for being > 0.

Code for click and enter the submit button :

 $(":input").bind("click keypress", function(evt) {   
     var keyCode = evt.which || evt.keyCode;
     var sender = evt.target;                 
     if (keyCode == 13 || sender.type == "submit") {                        
        evt.preventDefault();  
        // add your validations
     }
     // and submit the form
 }

var atleast = 1;
function validate() {
    debugger;
    var CHK = document.getElementById("<%=chk1");
    var checkbox = document.getElementsByTagName("input");
    var counter = 0;
    for (var i = 0; i < checkbox.length; i++) {
        if (checkbox[i].checked) {
            counter++;
        }
    }
    if (atleast > counter) {
        alert("Please select atleast " + atleast + " employee ");
        return false;
    }
    return true;
}

<button type="submit" name="Initiate" value="Initiate" on click="return validate()" id=" initiate"></button>