how to re-set Phillips cordless phone?

I have two Phillips cordless handsets. Both screens say "Searching". I have replaced all the 1.2 V Nmih batteries & charged overnight, but still can get no dialling tone or outside line. Do I need to re-set, and if so how?
I can't find the model no. but is there a generic solution for re-setting? Or any other answer?
Thanks !