jQuery.fn.replace = function() {
    var stack = [];
    return this.domManip(arguments, true, 1, function(a){
        this.parentNode.replaceChild( a, this );
        stack.push(a);
    }).pushStack( stack );
};
// jQuery extension to check checkboxes
jQuery.fn.check = function(b) {
    return this.each(function() {
        this.checked = b;
    });
};