can't get the syntax right in this pyqt3 command?

view story

http://www.linuxquestions.org – Code:     x = self.spinbox37.value() * 40           y = self.spinbox38.value() * 40           printer = str(self.comboBox4.currentText())           print_cmd = 'echo "IN;PU" x "," y | lpr -P %s %s'           self.LCDNumber18.display(x)           self.LCDNumber19.display(y)           #print_cmd = 'echo "IN;PU2100,11300;" | lpr -P %s %s'           os.system(print_cmd % (printer, "")) In the above line I'm trying to use the x and y variable set by the spinbox values, I just can't seem to get the variable value it keeps giving me a literal x and y in the print command. The commented out print command with the forced x and y works great. Any ideas or help would be appreciated! (HowTos)