user newbie - please start your own new thread for your question. It can be difficult enough answering 1 person's questions on a thread without getting everyone confused.
The drawing posted by srinivas karthik does not appear to make sense to me - yes, you can drive a ULN2003 input with the 3.3V I/O on the LPC2148, but there is no 5V connection on the processor. I am assuming that you are trying to activate the relay by grounding one end of the coil through the ULN2003 output. You need to set the GPIO pin function and state using the GPIO peripheral registers IOPIN, IODIR, IOSET, IOCLR. Do you have a manual or datasheet for the processor?