function image_gradient($size_y, $start_color, $end_color, $newfilename = null)
{
	if (isset($start_color) && isset($end_color))
	{
		$this->image_create(1, $size_y);
			
		if ($this->image)
		{
			$start_color = array("red" => base_convert(substr(ltrim(trim($start_color), "#"), 0, 2), 16, 10), "green" => base_convert(substr($start_color, 2, 2), 16, 10), "blue" => base_convert(substr($start_color, 4, 2), 16, 10));
			$end_color = array("red" => base_convert(substr(ltrim(trim($end_color), "#"), 0, 2), 16, 10), "green" => base_convert(substr($end_color, 2, 2), 16, 10), "blue" => base_convert(substr($end_color, 4, 2), 16, 10));
				
			for ($y = 0; $y < imagesy($this->image); $y++)
			{
				if ($start_color['red'] < $end_color['red'])
					$start_color['red']++;	
						
				if ($start_color['green'] < $end_color['green'])
					$start_color['green']++;
						
				if ($start_color['blue'] < $end_color['blue'])
					$start_color['blue']++;
					
				$color = imagecolorallocate($this->image, $start_color['red'], $start_color['green'], $start_color['blue']);
				imagesetpixel($this->image, 1, $y, $color);
			}
				
			if ($newfilename)
			{
				if (substr(-4, 4) == '.png')
				{
					imagepng($this->image, $newfilename);
				}
				else
				{
					$newfilename = "{$newfilename}.png";
					imagepng($this->image, $newfilename);
				}
			}
			else
			{
				$newfilename = time().'.png';
				imagepng($this->image, $newfilename);
			}
			
			return $newfilename;
		}
		else
		{
			return false;
		}
	}
	else
	{
		return false;
	}
}