Marc, thank you for fast answer.
This also explain why i had troubles with a function like
function drawImage(){ if (this._image instanceof ScriptUIImage){ this.graphics.drawImage(this._image, 0,0); } else{ this.graphics.drawOSControl(); }; };
myDropDown.onDraw = drawImage : if the dropddown has a "_image" property, it was drawing the image as expected, else it was drawing nothing.
But i still have a problem with drawString(), completely unrelated to drawOSControl().
I'll open a new thread then, maybe tomorrow!
Xavier