Function code to turn on wireless capabilities

Okay, my 7 month old banged on the keys of the laptop and managed to turn off the wireless capabilities on my laptop.  I have a Dell Inspirion 1545, and the troubleshooting message that comes up when I diagnose the problem on my computer says to flip the switch or type in some function key combination.  I looked and I don't have a switch, so can anyone help me find this code?