(function($) {

$.blockUI = function(msg, css) {
		$.blockUI.impl.install(window, msg, css);
};
$.unblockUI = function() {
		$.blockUI.impl.remove(window);
};
$.fn.block = function(msg, css) {
		return this.each(function() {
		if (!this.$pos_checked) {
						if ($.css(this,"position") == 'static')
								this.style.position = 'relative';
						this.$pos_checked = 1;
				}
				$.blockUI.impl.install(this, msg, css);
		});
};
$.fn.unblock = function() {
		return this.each(function() {
				$.blockUI.impl.remove(this);
		});
};

// override these in your code to change the default messages and styles
$.blockUI.defaults = {
		// the message displayed when blocking the entire page
		pageMessage:    '<h1>Please wait...</h1>',
		// the message displayed when blocking an element
		elementMessage: '', // none
		// styles for the overlay iframe
		overlayCSS:  { backgroundColor: '#000', opacity: '0.5' },
		// styles for the message when blocking the entire page
		pageMessageCSS:    { width:'250px', margin:'-50px 0 0 -125px', top:'50%', left:'50%', textAlign:'center', color:'#000', backgroundColor:'#000', border:'3px solid #aaa' },
		// styles for the message when blocking an element
		elementMessageCSS: { width:'250px', padding:'10px', textAlign:'center', backgroundColor:'#000'},
		// allow body element to be stetched in ie6
		ie6Stretch: 1
};

// the gory details
$.blockUI.impl = {
		pageBlock: null,
		op8: window.opera && window.opera.version() < 9,
		ffLinux: $.browser.mozilla && /Linux/.test(navigator.platform),
		ie6: $.browser.msie && typeof XMLHttpRequest == 'function',
		install: function(el, msg, css) {
				var full = (el == window), noalpha = this.op8 || this.ffLinux;
				if (full && this.pageBlock) this.remove(window);
				// check to see if we were only passed the css object (a literal)
				if (msg && typeof msg == 'object' && !msg.jquery && !msg.nodeType) {
						css = msg;
						msg = null;
				}
				msg = msg ? (msg.nodeType ? $(msg) : msg) : full ? $.blockUI.defaults.pageMessage : $.blockUI.defaults.elementMessage;
				var basecss = jQuery.extend({}, full ? $.blockUI.defaults.pageMessageCSS : $.blockUI.defaults.elementMessageCSS);
				css = jQuery.extend(basecss, css || {});
				var f = ($.browser.msie) ? $('<iframe class="blockUI" style="z-index:1000;border:none;margin:0;padding:0;position:absolute;width:100%;height:100%;top:0;left:0" src="javascript:false;document.write(\'\');"></iframe>')
													 : $('<div class="blockUI" style="display:none"></div>');
				var w = $('<div class="blockUI" style="z-index:1001;cursor:not-allowed;border:none;margin:0;padding:0;width:100%;height:100%;top:0;left:0"></div>');
				var m = full ? $('<div class="blockUI blockMsg" style="z-index:1002;cursor:default;padding:0;position:fixed"></div>')
										 : $('<div class="blockUI" style="display:none;z-index:1002;cursor:not-allowed;position:absolute"></div>');
				w.css('position', full ? 'fixed' : 'absolute');
				if (msg) m.css(css);
				if (!noalpha) w.css($.blockUI.defaults.overlayCSS);
				if (this.op8) w.css({ width:''+el.clientWidth,height:''+el.clientHeight }); // lame
				if ($.browser.msie) f.css('opacity','0.0');

				$([f[0],w[0],m[0]]).appendTo(full ? 'body' : el);
				if (full) this.pageBlock = m[0];

				// ie7 needs to use absolute positioning to account for activex issues (when scrolling)
				var activex = $.browser.msie && $('object,embed', full ? null : el).length > 0
				if (this.ie6 || activex) { 
						// stretch content area if it's short
						if (full && $.blockUI.defaults.ie6Stretch && $.boxModel)
								$('html,body').css('height','100%');

						// simulate fixed position
						$.each([f,w,m], function(i) {
								var s = this[0].style;
								s.position = 'absolute';
								if (i < 2) {
										full ? s.setExpression('height','document.body.scrollHeight > document.body.offsetHeight ? document.body.scrollHeight : document.body.offsetHeight + "px"') : s.setExpression('height','this.parentNode.offsetHeight + "px"');
//                    full ? s.setExpression('height','document.body.scrollHeight + "px"') : s.setExpression('height','this.parentNode.offsetHeight + "px"');
										full ? s.setExpression('width','jQuery.boxModel && document.documentElement.clientWidth || document.body.clientWidth + "px"')
												 : s.setExpression('width','this.parentNode.offsetWidth + "px"');
								}
								else {
										full ? s.setExpression('top','(document.documentElement.clientHeight || document.body.clientHeight) / 2 - (this.offsetHeight / 2) + (blah = document.documentElement.scrollTop ? document.documentElement.scrollTop : document.body.scrollTop) + "px"')
												 : s.setExpression('top','this.parentNode.top');
										s.marginTop = 0;
								}
						});
				}
				this.bind(1, el);
				m.append(msg).show();
				if (msg.jquery) msg.show();
				full ? setTimeout(this.focus, 200): this.center(m[0]);
				if (this.op8) this.simulate(true,el);
		},
		remove: function(el) {
				this.bind(0, el);
				var full = el == window;
				if (full) {
						$('body').children().filter('.blockUI').remove();
						this.pageBlock = null;
				}
				else $('.blockUI', el).remove();
				if (this.op8) this.simulate(false,el);
		},
		// event handler to suppress keyboard/mouse events when blocking
		handler: function(e) {
				if (e.keyCode && e.keyCode == 9) return true;
				if ($(e.target).parents('div.blockMsg').length > 0)
						return true;
				return $(e.target).parents().children().filter('div.blockUI').length == 0;
		},
		// bind/unbind the handler
		bind: function(b, el) {
				var full = el == window;
				// don't bother unbinding if there is nothing to unbind
				if (!b && (full && !this.pageBlock || !full && !el.$blocked)) return;
				if (!full) el.$blocked = b;
				var $e = full ? $() : $(el).find('a,:input');
				$.each(['mousedown','mouseup','keydown','keypress','keyup','click'], function(i,o) {
						$e[b?'bind':'unbind'](o, $.blockUI.impl.handler);
				});
		},
		// simulate blocking in opera8
		simulate: function(dis, el) {
				var full = el == window;
				$(':input', full ? 'body' : el).each(function() {
						if (full && $(this).parents('div.blockMsg').length > 0) return;
						if (this.$orig_disabled == undefined)
								this.$orig_disabled = this.disabled;
						var d = dis || this.$orig_disabled;
						if (d) this.$orig_disabled = this.disabled;
						this.disabled = d;
				});
		},
		focus: function() {
				if (!$.blockUI.impl.pageBlock) return;
				var v = $(':input:visible:enabled', $.blockUI.impl.pageBlock)[0];
				if (v) v.focus();
		},
		center: function(el) {
		var p = el.parentNode, s = el.style;
				var l = (this.sz(p,1) - this.sz(el,1))/2, t = (this.sz(p,0) - this.sz(el,0))/2;
				s.left = l > 0 ? (l+'px') : '0';
				s.top  = t > 0 ? (t+'px') : '0';
		},
		sz: function(el, w) { return parseInt($.css(el,(w?"width":"height"))); }
};

})(jQuery);