Help to add error checking to this function

[Meapserie]

I need to add some error checking to this function to make sure that the imagegif() and imagecolorset() functions are successful. The usual cause for failure is a permissions issue where the spot2.gif file is not writable. However, when I change the spot2.gif to read only, a condition that should trigger the "else" conditions, the echo'd javascript alert is not firing.\[code\]function set_theme_color_spot2($hex){ $info = hexToRGB($hex); $token = "../wp-content/themes/".get_option('template')."/styles/".get_option('myTheme')."/spot2.gif"; $token2 = "../wp-content/themes/".get_option('template')."/styles/".get_option('myTheme')."/spot2-template.gif"; if (file_exists($token2) && is_writable($token)) { $img = imagecreatefromgif("../wp-content/themes/".get_option('template')."/styles/".get_option('myTheme')."/spot2-template.gif"); $color = imagecolorallocate($img, $info["red"], $info["green"], $info["blue"]); imagecolorset($img, 0, $info["red"], $info["green"], $info["blue"]); imagegif($img, $token); $themecolor = get_option('myTheme').'_color4'; update_option($themecolor, $hex); } else { echo "<script type='text/javascript'>alert('The template colors could not be changed because your current file permissions are too restrictive. Make sure the files in the styles directory are set to 644');</script>"; }}\[/code\]