php/sql problem

[raider00321]

Hey guys, I'm trying to make a SQL statement that should only affect certain rows in my database but with no luck. Ive tried this code.

    //population
	$medpopulatecron=mysql_query("SELECT medpopulate,middleclasspop FROM $table") 

mysql_query("UPDATE $table SET medpopulate=medpopulate*'$medpopgrowth' WHERE medpopulate < middleclasspop");

mysql_query("UPDATE $table SET upperpopulate=upperpopulate*'$uppopgrowth' WHERE upperpopulate < upperclasspop");

mysql_query("UPDATE $table SET lowerpopulate=lowerpopulate*'$lwrpopgrowth' WHERE lowerpopulate < lowerclasspop ");

//populate set max
mysql_query("UPDATE $table SET medpopulate=middleclasspop WHERE medpopulate > middleclasspop");

mysql_query("UPDATE $table SET upperpopulate=upperclasspop WHERE upperpopulate > upperclasspop");

mysql_query("UPDATE $table SET lowerpopulate=lowerclasspop WHERE lowerpopulate > lowerclasspop ");

This however just set the database to either the lowest possible number for the database, to the highest total number. What can i do to fix this problem???