function checkEnter(e,caller) //e is event object passed from function invocation
{
    var characterCode //literal character code will be stored in this variable

    if(e && e.which ||e.which == 0)
    { //if which property of event object is supported (NN4)
        e = e
        characterCode = e.which //character code is contained in NN4's which property
    }
    else
    {
        e = event
        characterCode = e.keyCode //character code is contained in IE's keyCode property
    }

    if(characterCode == 13)//if generated character code is equal to ascii 13 (if enter key)
    {
        document.getElementById(caller).click();
        return false
    }
    else
    {
        return true
    }
}