whats this error??

CCP1CON=0B00000100; //every falling edge of clock interrupts it
^
Error[Pe065]: C:\CFILES~1\CPROJECT\INTERR~3.C 6 : expected a ";"


I am using the PIC 16f877 and trying to cause interrupts

Are you missing ; anywhere?

Post more of your code, maybe the error is not on line 6 as your compiler suggests.

The error is probably on the line right before where it shows the error. Spaces and carrage returns are optional in C (you can put your whole program on one line if you felt like it) so sometimes the compiler is wrong about what line the error is actually on.