Basic validation / checkbox and text field

Question

I am trying to validate "mytextinput" only if the checkbox with the id="checkbox" is checked. No luck! Tried these variations of script:

    if (myform.mytextinput.value=="" && document.getElementById("checkbox").checked) {
    alert ('Please enter something!');
    return false;}

---

    if (myform.mytextinput.value=="" && document.getElementById("checkbox").checked==true) {
    alert ('Please enter something!');
    return false;}

---

    if (myform.mytextinput.value=="" || document.getElementById("checkbox").checked) {
    alert ('Please enter something!');
    return false;}

What am I doing wrong?

Answer 1

You could make it this way. The validation of your input will only executed if your checkbox is checked.

if(document.getElementById("checkbox").checked){
        if (myform.mytextinput.value == "") {
            alert("Please enter something!");
            return false;
        }

    //... more validation
    }

In your solution you're validating the checkbox AND your input but possibly it's not necessary to check the input because the checkbox isn't checked.

JSfiddle

Answer 2

If you want the users to write something in the textfield, but only validate if the checkbox with id checkbox is checked, this should work:

if (myform.mytextinput.value.length < 1 && document.getElementById("checkbox").checked) {
    alert ('Please enter something!');
    return false;
}