function needed asap

[brand]

$noi = mysql_fetch_array(mysql_query("SELECT timesent FROM ibwf_private WHERE id='".$pmid."'")); 
 $var1 = date("his",$noi[0]); 
 $var2 = time (); 
 $var21 = date("his",$var2); 
 $var3 = $var21 - $var1; 
 $var4 = date("s",$var3); 
 echo "<b>This pm was sent </b>";
 $remain = time() - $noi[0]; 
 $idle = gettimemsg($remain); 
 echo "$idle ago<br/>";

when i add this on wapdesire v_2 script it says there is no function for gettimemsg

can some one help please and thanks to any one that can help me with this thanks