Tooltip on button click using jquery

Question

How can I show an error message using tooltip on click of a button and that too if there is error, else the button should just work fine to submit the form?

Here is what I have tried with modal dialog

$.fx.speeds._default = 1000;
$(function() {
 $('#dialog').dialog({autoOpen:false,show:'blind',hide:'explode'});
 $('#savej').click(function(){$('#dialog').dialog('open');return false;});
});

Answer 1

$('#savej').click(function(e){
    if (hasErrors()) { // Some checking for errors
        e.preventDefault();
        $('#dialog').dialog('open');
    }
});