public function setStamp( $stampFile) {
		$imageinfos = @getimagesize($stampFile);
		$width  = $imageinfos[0];
		$height = $imageinfos[1];
		$type   = $imageinfos[2];
		
		if ($this->stampImage) imagedestroy( $this->stampImage);
		
		$this->stampImage=$this->readImage($stampFile, $type);
		
		if (!$this->stampImage) {
			$this->errorMsg="Error on loading '$stampFile', stamp image must be a valid PNG or JPEG file.";
			return(false);
		}
		else {
			$this->stampWidth=$width;
			$this->stampHeight=$height;
			return(true);
		}
	}