reset check engine light?; 98F150 4x4

I replaced the egr valve that was flagged as causing the check engine light to come on. I replace it, but don't know what's the proper procedure to
reset the light. I tried momentarily disconnecting the battery, but that didn't work (unless its still being set by another problem). Anyone know how to do a reset? thanks.

Have the codes read again and post EXACT code number that is stored. A lot of times an EGR vave is sold for a problem in another part of the EGR system.