Here is an example on how to customize a selector in jquery:

// Add this code anywhere you want (after jQuery has been loaded). 
// Edit it to add your own expressions. 
jQuery.extend(jQuery.expr[':'], { 
    /////////////////////////////////////////////////////////// 
    // form elements that are submitable based on these criteria 
    //    element is not disabled 
    //    element has a selected or checked attribute 
    //    element is a textarea 
    //    element is an input of type text or hidden 
    // 
    //  @usage: $(':submitable') 
    //  @usage: $('#myForm :submitable') 
    submitable: function(a) { 
        return !a.disabled&&(a.selected||a.checked||(a.nodeName.toUpperCase()=='TEXTAREA')||(a.nodeName.toUpperCase()=='INPUT'&&(a.type=='text'||a.type=='hidden'||a.type=='password'))); 
    }, 
    /////////////////////////////////////////////////////////// 
    // elements that have a type attribute not equal to hidden 
    //    use if you want to select all input elements that are not hidden 
    //  @usage: $('input:nothidden') 
    nothidden: function(a) { 
        return a.type&&a.type!='hidden'; 
    } 
})