diff --git a/js/dwz.dialog.js b/js/dwz.dialog.js
index a59b971996ee7deeb96748aa3f5a0455c19d9e40..80fc15d77c13d7d1f658a2d15dc152387a06ed94 100644
--- a/js/dwz.dialog.js
+++ b/js/dwz.dialog.js
@@ -180,6 +180,14 @@
 		},
 		_init:function(dialog, options) {
 			var op = $.extend({}, this._op, options);
+			   if(op.width&&/.*%$/.test(op.width)){
+				   var sw = window.innerWidth || document.documentElement.clientWidth || document.body.clientWidth;
+				   op.width = Number(op.width.substring(0,op.width.length-1))*sw/100;
+			   }
+			   if(op.height&&/.*%$/.test(op.height)){
+				   var sh = window.innerHeight || document.documentElement.clientHeight || document.body.clientHeight;
+				   op.height = Number(op.height.substring(0,op.height.length-1))*sh/100;
+			   }
 			var height = op.height>op.minH?op.height:op.minH;
 			var width = op.width>op.minW?op.width:op.minW;
 			if(isNaN(dialog.height()) || dialog.height() < height){
@@ -364,4 +372,4 @@
 			$(window).trigger(DWZ.eventType.resizeGrid);
 		}
 	};
-})(jQuery);
\ No newline at end of file
+})(jQuery);
diff --git a/js/dwz.ui.js b/js/dwz.ui.js
index 131b3967862783a218b238095e301acfafe65c1a..448039e1c25af0a5389dc32e9ed114d35630f44f 100644
--- a/js/dwz.ui.js
+++ b/js/dwz.ui.js
@@ -221,6 +221,14 @@ function initUI($p){
 			var options = {};
 			var w = $this.attr("width");
 			var h = $this.attr("height");
+			   if(w&&/.*%$/.test(w)){
+				   var sw = window.innerWidth || document.documentElement.clientWidth || document.body.clientWidth;
+				   w = Number(w.substring(0,w.length-1))*sw/100;
+			   }
+			   if(h&&/.*%$/.test(h)){
+				   var sh = window.innerHeight || document.documentElement.clientHeight || document.body.clientHeight;
+				   h = Number(h.substring(0,h.length-1))*sh/100;
+			   }
 			if (w) options.width = w;
 			if (h) options.height = h;
 			options.max = eval($this.attr("max") || "false");