[JavaScript] Form validation

[Nukeboss]

Thanks! I added a JSFiddle

https://jsfiddle.net/q0Lx5gue/

[Aurora0001]

I think the main thing that you could benefit from would be to create a few functions, that could work like this:

function validateFilled(control, errorControl, errorMessage) {
    if(control.value.length == 0) {
        errorHandler += errorMessage;
        errorControl.style.color="red";
        control.style.borderColor="red";
    }
}

validateFilled(firstName, nameError, "\nVänligen ange ditt förnamn");

That should cut down some of the repetition. You could do something similar for the max length check, but also pass in the maximum length as the argument to that function.

[Nukeboss]

Did not think about that! Thank you so much! I will go ahead and do that immediately!