AT89C2051 based digital door lock system

Can you post your Proteus dsn file ?

i have compiled the files you have sent me but the total hex file is of 6KB
files compiled are : startup.a51
lcd.c
keypad.c
main.c
delay.c
still its not working i have attached the proteus file of my project in attachments
do reply.

Don't worry about the size of the hex file, the actual code is smaller.
I tried your simulation and you're right, it displays a message then nothing !
It is probably a Proteus thing.
Check the keyboard,it may need pullups,or different connections.
Consider using push buttons wired as a grid instead.

what is the version of proteus you're using? coz in one of the proteus version keypad is buggy. you press the key and it stays down and do not work afterwards. if that is the case with you then probably your proteus version needs to be udpated or use different keypad. use 4x4 in form of 4x3.

thanks i will try the troubleshooting options you both mentioned.have a nice day .
i will keep updating about project status.