How to show selected items in multiple select Box

[vidz]

This is my mutiple select drop down box in edit page. Problem here is that this shows only one selected items. It doesn't show all selected items in it. How can i correct this?

 <?php
		 $query="SELECT * FROM lab";
		$dropdown = "<select name='labid[]' multiple='multiple'  style='height:80px;' size='5' id='lab'>";
		//$dropdown .= "<option value=''>Select lab to assign </option>";
		$result2 = mysql_query ($query);
        while($row2 = mysql_fetch_assoc($result2)) 
		{

  $dropdown .= "\r\n<option value='{$row2['lab_id']}'";
            while($row1 = mysql_fetch_assoc($result1)) 
		      {
				 if(($row1['lab_id'])==($row2['lab_id']))
				  {
					  $dropdown .=" selected='selected'";
				  }
			 }
  $dropdown .= ">{$row2['l_name']}</option>";
		}
		$dropdown .= "\r\n</select>";
		echo $dropdown;
       ?>

[Weedpacket]

Once the inner loop has gone through all the rows in [font=monospace]$result1[/font] it's at the end. The next time you get to the inner loop, it's still at the end.

$selected_ids = array();
while($row1 = mysql_fetch_assoc($result1))
{
    $selected_ids[] = $row1['lab_id'];
}
while($row2 = mysql_fetch_assoc($result2);
{
    ....
    if(in_array($row2['lab_id'], $selected_ids))
    {
        ....
    }
}

Also, note that use of the MySQL extension in new development is discouraged.

[vidz]

Thanku very much Weedpacket . But i have come up with new idea. Its really simple and working tooo. see

 $query="SELECT * FROM lab";
		$dropdown = "<select name='labid[]' multiple='multiple'  style='height:80px;' size='5' id='lab'>";
		//$dropdown .= "<option value=''>Select lab to assign </option>";
		$result2 = mysql_query ($query);
        while($row2 = mysql_fetch_assoc($result2))       

		{

  $dropdown .= "\r\n<option value='{$row2['lab_id']}'";
            foreach(mysql_fetch_array($result1) as $row1)    // line 292
		      {
				 if(($row1['lab_id'])==($row2['lab_id']))
				  {
					  $dropdown .=" selected='selected'";
				  }
			 }
  $dropdown .= ">{$row2['l_name']}</option>";
		}
		$dropdown .= "\r\n</select>";
		echo $dropdown;

but the problem is there is a warning msg Warning: Invalid argument supplied for foreach() in F:\xampplite\htdocs\chem1\admin\edituser.php on line 292 can u see wat is wrong here

[Weedpacket]

Looks nasty to me, but if you say it's simpler .... But maybe it's too simple and that's why you're getting the message - you're failing to take into account what happens when you get to the end of the result set in [font=monospace]$result1[/font], where [man]mysql_fetch_assoc[/man] will return false instead of an array.