Conditional Shortcode problem

hey guys.. i am creating a shortcode that should return a specific image among other stuff depending on the user entered value

here it is:

function postInfoBoxSc( $atts ) {
    extract( shortcode_atts( array(
        'subject' => 'Category type',
        'difficulty' => 'User Types',
        'completiontime' => 'completion Time'
    ), $atts ) );

		// Set image acorring to guide type
		if ($subject == 'wordpress') {
			$subjectImg = '<img src="'.get_bloginfo('template_url').'/img/postInfoBox/wordpress.png" alt="מדריך וורדפרס" />';
		} elseif ($subject == 'web design') {
			$subjectImg = '<img src="'.get_bloginfo('template_url').'/img/postInfoBox/webDesign.png" alt="מדריך בניית אתרים" />';
		} elseif ($subject == 'facebook') {
			$subjectImg = '<img src="'.get_bloginfo('template_url').'/img/postInfoBox/facebook.png" alt="מדריך פייסבוק" />';
		} elseif ($subject == 'RSS') {
			$subjectImg = '<img src="'.get_bloginfo('template_url').'/img/postInfoBox/rss.png" alt="מדריך RSS" />';
		}

    return '
	<br class="clear" />
	<div class="postInfoBox">
		'. $subjectImg .'
		<h5>Guide information:</h5>
		<ul>
			<li><strong>Category:</strong> '. $subject .'</li>

					<li><strong>User Lever:</strong> '. $difficulty .'</li>

					<li><strong>completion Time:</strong> '. $completiontime .'</li>

		</ul>
	</div>
	';
}
add_shortcode( 'postInfoBox', 'postInfoBoxSc' );

No matter what i do the value for subject isnt being checkd..
What am i doing wrong?