본문에서 썸네일의 이미지가 없을시 노이미지 출력을 어떻게 해야할까요?

function get_thumbnail2($bo_table, $img, $width, $height=0, $alt, $view=0){    $str = '';    $file = G5_DATA_PATH.'/file/'.$bo_table.'/'.$img;    if(is_file($file))        $size = @getimagesize($file);    if($size[2] < 1 || $size[2] > 3)        return '';    $img_width = $size[0];    $img_height = $size[1];    $filename = basename($file);    $filepath = dirname($file);    if($img_width && !$height) {        $height = round(($width * $img_height) / $img_width);    }    $thumb = thumbnail($filename, $filepath, $filepath, $width, $height, false, false, 'center', true, $um_value='80/0.5/3');    if($thumb) {        $file_url = str_replace(G5_PATH, G5_URL, $filepath.'/'.$thumb);        $str = '<a href="'.$file_url.'" target="_blank" class="popup_item_image"><img src="'.$file_url.'" alt="'.$alt.'"></a>';    }    if($view == 1) return $str;}

<div id="sit_pvi_big">						<?php for($i = 0; $i <= count($view['file']); $i++) { // 이미지 뷰 ?>            <?php if($view['file'][$i]['file']){                get_thumbnail2($bo_table, $view['file'][$i]['file'], 400, 300, $view['file'][$i]['bf_content']);            ?>							<?php echo get_thumbnail2($bo_table, $view['file'][$i]['file'], 400, 300, $view['file'][$i]['bf_content'], 1); ?>			           <?php } ?>            <?php } ?>					</div>					<div id="sit_pvi_thumb">						<?php for($i = 0; $i <= count($view['file']); $i++) { // 이미지 뷰 ?>            <?php if($view['file'][$i]['file']){                get_thumbnail($bo_table, $view['file'][$i]['file'], 400, 300, $view['file'][$i]['bf_content']);            ?>							<?php echo get_thumbnail($bo_table, $view['file'][$i]['file'], 60, 60, $view['file'][$i]['bf_content'], 1); ?>			           <?php } ?>            <?php } ?>					</div>