diff --git a/js/buttonbehaviors.js b/js/buttonbehaviors.js
index 23306ed..16fcfb8 100644
--- a/js/buttonbehaviors.js
+++ b/js/buttonbehaviors.js
@@ -189,6 +189,7 @@ function initButtonBehavior() {
 }
 function stopPrint() {
   console.log("f:stopPrint() >> sendPrintCommands = " + sendPrintCommands);
+  if (!confirm("Weet je zeker dat je de huidige print wilt stoppen?")) return;
   if (sendPrintCommands) printer.stop();
   setState(Printer.STOPPING_STATE,printer.hasControl);
 }
@@ -229,6 +230,7 @@ function print(e) {
     console.log("f:print >> not enough points!");
   }
 
+  alert("Je tekening zal nu geprint worden.");
 
   //	$.post("/doodle3d.of", { data:output }, function(data) {
   //	btnPrint.disabled = false;
@@ -295,17 +297,17 @@ function previewTwistRight(redrawLess) {
 
 function update() {
 	setState(printer.state,printer.hasControl);
-	
+
 	thermometer.update(printer.temperature, printer.targetTemperature);
 	//TODO: update progress
 }
 
-function setState(newState,newHasControl) { //TODO add hasControl 
+function setState(newState,newHasControl) { //TODO add hasControl
 	if(newState == state && newHasControl == hasControl) return;
-	
+
 	console.log("setState: ",state," > ",newState," ( ",newHasControl,")");
 	setDebugText("State: "+newState);
-	
+
 	// print button
 	var printEnabled = (newState == Printer.IDLE_STATE && newHasControl);
 	if(printEnabled) {
@@ -316,7 +318,7 @@ function setState(newState,newHasControl) { //TODO add hasControl
 			btnPrint.addClass("disabled"); // disable print button
 			btnPrint.unbind('touchstart mousedown');
 	}
-	
+
 	// stop button
 	var stopEnabled = ((newState == Printer.PRINTING_STATE || newState == Printer.BUFFERING_STATE) && newHasControl);
 	if(stopEnabled) {
@@ -327,7 +329,7 @@ function setState(newState,newHasControl) { //TODO add hasControl
 		btnStop.addClass("disabled");
 		btnStop.unbind('touchstart mousedown');
 	}
-	
+
 	// thermometer
 	switch(newState) {
 		case Printer.UNKNOWN_STATE:
@@ -338,18 +340,18 @@ function setState(newState,newHasControl) { //TODO add hasControl
 			thermometer.show();
 			break;
 	}
-	
+
 	// progress indicator
 	switch(newState) {
-		case Printer.PRINTING_STATE: 
+		case Printer.PRINTING_STATE:
 			displayProgress.show(); // TODO: Show progress
 			break;
 		default:
 			displayProgress.hide(); // TODO: hide progress
 			break;
 	}
-	
+
 	prevState = state;
 	state = newState;
 	hasControl = newHasControl;
-}
\ No newline at end of file
+}
diff --git a/js/gcodeGenerating.js b/js/gcodeGenerating.js
index 68cc3dc..3b4db6b 100644
--- a/js/gcodeGenerating.js
+++ b/js/gcodeGenerating.js
@@ -10,7 +10,7 @@ gcodeStart.push("G92 E0"); 					// zero the extruded length
 gcodeStart.push("G1 F200 E10");			// extrude 10mm of feed stock
 gcodeStart.push("G92 E0");					// zero the extruded length again
 //gcodeStart.push("G92 X-100 Y-100 E0"); // zero the extruded length again and make center the start position
-gcodeStart.push("G1 F9000");				
+gcodeStart.push("G1 F9000");
 gcodeStart.push("G90"); 						// absolute positioning
 gcodeStart.push("M117 Printing Doodle...  ");	// display message (20 characters to clear whole screen)
 
@@ -101,9 +101,9 @@ function generate_gcode(callback) {
   console.log("");
   //*/
 
-  // max amount of real world layers 
+  // max amount of real world layers
   var layers = maxObjectHeight / layerHeight; //maxObjectHeight instead of objectHeight
-  
+
   // translate numLayers in preview to objectHeight in real world
   //objectHeight = Math.ceil(numLayers / 5); // in settings objectHeight = 20, in previewRendering_v01.js numLayers is 100, hence the / 5
   //objectHeight = numLayers; // in settings objectHeight = 20, in previewRendering_v01.js numLayers is 100, hence the / 5
@@ -113,7 +113,7 @@ function generate_gcode(callback) {
   var rStepGCode = rStep * maxNumLayers/layers; ///maxNumLayers*maxObjectHeight;
   // correct direction
   rStepGCode = -rStepGCode;
-	
+
   // todo hier een array van PATHS maken wat de losse paths zijn
 
   // copy array without reference -> http://stackoverflow.com/questions/9885821/copying-of-an-array-of-objects-to-another-array-without-object-reference-in-java
@@ -125,10 +125,11 @@ function generate_gcode(callback) {
 //  return;
 
   console.log("printer temperature: ",temperature);
-	gcode.push("M109 S" + temperature); // set target temperature and wait for the extruder to reach it
+	gcode.push("M104 S" + temperature); // set target temperature and do not wait for the extruder to reach it
+  //gcode.push("M109 S" + temperature); // set target temperature and wait for the extruder to reach it
   // add gcode begin commands
   gcode = gcode.concat(startGcode);
-	
+
   //gcode.push("M109 S" + temperature); // set target temperature and wait for the extruder to reach it
 
   var layers = maxObjectHeight / layerHeight; //maxObjectHeight instead of objectHeight
@@ -204,7 +205,7 @@ function generate_gcode(callback) {
       }
     }
 //    console.log("f:generategcode() >> paths.length: " + paths.length);
-		
+
     // loop over the subpaths (the separately drawn lines)
     for (var j = 0; j < paths.length; j++) { // TODO paths > subpaths
       // this line is probably for drawing efficiency, alternating going from 0->end and end->0 (i.e. to and fro)
@@ -234,7 +235,7 @@ function generate_gcode(callback) {
 //          console.log("enableTraveling && isTraveling >> doRetract: " + doRetract + ", retractionspeed: " + retractionspeed);
           if (doRetract) gcode.push("G0 E" + (extruder - retractionamount).toFixed(3) + " F" + (retractionspeed * 60).toFixed(3)); //retract
           gcode.push("G0 X" + to.x.toFixed(3) + " Y" + to.y.toFixed(3) + " Z" + z.toFixed(3) + " F" + (travelSpeed * 60).toFixed(3));
-          if (doRetract) gcode.push("G0 E" + extruder.toFixed(3) + " F" + (retractionspeed * 60).toFixed(3)); // return to normal 
+          if (doRetract) gcode.push("G0 E" + extruder.toFixed(3) + " F" + (retractionspeed * 60).toFixed(3)); // return to normal
         } else {
 //          console.log("       else");
           extruder += prev.distance(to) * wallThickness * layerHeight / filamentThickness;
@@ -343,4 +344,4 @@ Point.prototype = {
   toString: function() {
     console.log("x:" + this.x + ", y:" + this.y);
   }
-}
\ No newline at end of file
+}