อยากรู้วิธีนำเอาข้อมูลจาก database มาบวกลบกัน แล้วแสดงผล

<?php
$sql="select * from `".$tb_prefix."deposit` Order by DepositID DESC  limit 50 ";
$result=mysql_db_query($dbName,$sql);
while ($record=mysql_fetch_array($result)){
$DepositID=$record[DepositID];
$Username=$record[Username];
$DepositBank=$record[DepositBank];
$DepositAmount=$record[DepositAmount];
$Channel=$record[Channel];
$Deposittime=$record[Deposittime];
$Staff=$record[Staff];
$Date=$record[Date];

echo"	
<table width=\"1100\" border=\"0\" cellspacing=\"1\" cellpadding=\"0\">


<tr>
			<td width=\"100\" class=\"f7\" align=\"center\">$DepositID</td>
			<td width=\"150\" class=\"f7\" align=\"left\"><b>$Username</b></td>
			<td  width=\"150\" class=\"f7\" align=\"left\">$DepositBank</td>
			<td  width=\"150\" class=\"f7\" align=\"center\">$DepositAmount</td>
			<td  width=\"150\" class=\"f7\" align=\"center\">$Channel</td>
			<td  width=\"100\" class=\"f7\" align=\"center\">$Staff</td>
			<td  width=\"200\" class=\"f7\" align=\"center\">$Date</td>
</tr>
</table>

		";
}
 	?>