Question

$("input[type=text]").autocomplete({
minLength: 3,
source: function (request, response) {
        alert( $(this).val() );

I have 3 different input text box’s, but $(this).attr("id") or this.id both returned undefined

Answer 1

Not sure what is available inside source regarding this. You can always log it to console to see what is returned. The following pattern is helpful for implementing plugins on many elements

$("input[type=text]").each(function() {
    var id = this.id;
    $(this).autocomplete({
        minLength: 3,
        source: function(request, response) {
            alert(id);
        }
    });
});