php中关于进度条函数的实例分析

function ShowPercent($now,$total) 
{ 
 $percent = sprintf('%.0f',$now*100/$total); 
 $html = &#39;<table width="60%" style="border-collapse:separate" height="10" border="0" cellpadding="0" cellspacing="2" bgcolor="#fff"><tr>&#39;; 
 $count=0; 
 $pertr = 30; 
 while($count < $total) 
 { 
  $bgcolor = $count < $now ? &#39;green&#39;:&#39;#EEEEEE&#39;; 
  $html .= &#39;<td bgcolor="&#39;.$bgcolor.&#39;"> </td>&#39;; 
  $count++; 
  if($count%$pertr == 0) $html .= &#39;</tr><tr>&#39;; 
 } 
 $bgcolor2 = $now == $total ? &#39; style="font-weight:bold;color:green;"&#39;:&#39;&#39;; 
 $html .= &#39;<td&#39;.$bgcolor2.&#39; colspan="&#39;.($count%$pertr).&#39;">&#39;.$percent.&#39;%</td></tr></table>&#39;; 
 return $html; 
}