populate one field with a url slug based on value entered into another.

sluggable

 (function ( $ ) {
     
    $.fn.slugger = function(options) {

        var that = this;
        
        var settings = $.extend({
            target: null,
        }, options );
        if(settings.target) {
            
            settings.target.focus(function() {
                   $(this).addClass('dirty');
            });
            
            that.keyup(function() {
                if(!settings.target.hasClass('dirty')) {
                    settings.target.val($(that).val().toLowerCase().replace(/[^\w\s]/gi, '-').split(" ").join("-"));
                }
            
            })
         }

    };
    
}( jQuery ));