How to make your own PIC network

[skimask]

hi all

i need a help. i m using til81(phototransistor) in the receiver side,and an led r IRled or LED55 n the transmitter side.if the light intensity frm the transmitter s varied the output of the til81 should vary.but for me,i m using ordinary led,but the output s not varying if i provide any obstacle.plz any one help me to get the datasheet for til81plz help me

Sakthi

And you want to program it in C right?