8051 interrupts

I am trying to generate an interrupt when a byte is received via the serial port of an Atmel AT89C51. I am not having much luck. Here is my code:

#include <reg51.h>
#include <CTYPE.H>
#include <STDIO.H>
#include <INTRINS.H>

int big_d, count, dogg, i, j;

void rcv (void) interrupt 4 
{
	big_d = _getkey();
	count++;
	dogg = 1;
	RI = 0;
}

void main(void)
{
	SCON  = 0x50;		/* SCON: mode 1, 8-bit UART, enable rcvr */
    TMOD |= 0x20;       /* TMOD: timer 1, mode 2, 8-bit reload */   
    TH1   = 253;        /* TH1:  reload value for 9600 baud @ 11.0592MHz */
    TR1   = 1;          /* TR1:  timer 1 run */          
    TI    = 1;          /* TI:   set TI to send first char of UART */
	ES = 1;				/* enable serial interrupts */

	dogg = 0;
	count = 0x30;
do{
	putchar(count);
	for(j=0; j<255; j++)
	{
		for(i=0; i<255; i++)
		{
			_nop_();
			_nop_();
			_nop_();
			_nop_();
		}
	}
	if(dogg == 1)
	{
		putchar(count);
		printf("\n");
		putchar(big_d);
		printf("\n\n\n");
		dogg = 0;
	}
}while(1);
}