build variable names from variables

Hi list. I have a script with snippets of code looking like this: if ($row->category == RMA) {$num_RMA++;} if ($row->category == firmware) {$num_firmware++;} if ($row->category == other) {$num_other++;} .. echo "Category RMA: $num_RMA"; echo "Category firmware: $num_firmware"; echo "Category other: $num_other"; ... and so on for about twenty lines each of if and echo lines. This drives me nuts since Im sure there must be a better way of doing this. I have played with the idea of making a variable from the variables. something like '$num_$row->category++' but php pukes on me everytime I try. Could someone show me how to set this up using arrays or any other way that is more efficient and beatiful then using brute if() power? TIA -- R