2-Table query

I would like to update two tables at the same time. Currently I update each one separately, like so, $qryStr = "INSERT INTO table1 etc...."; odbc_exec($dbConn, $qryStr); $qryStr = "INSERT INTO table2 etc...."; odbc_exec($dbConn, $qryStr); Now, the problem there is if the first one passes, but the second fails, if the user tries to re-submit, the first now fails because of a primary key clash which is right, but then never executes the second one. This is what I THINK I should do, $qryStr = "(INSERT INTO table1 ( col1, col2 ) VALUES ( '$val1', '$val2' ) ) AND (INSERT INTO table2 ( col1, col2 ) VALUES ( '$val1', '$val2' ) )"; odbc_exec($dbConn, $qryStr); Any ideas are appreciated... I am not experienced with SQL query precedences, or operators, etc... A good reference for that very thing would be nice. Thanks in advance, RDB