In keil uVision 5 getting error c202 undefined identifier ...

#include <reg51.h>
#define LED P2

sbit sw = P1^0;
void delay(unsigned int );
main()
{
        sw=1;
        LED=1;
        while(1)
        {
                if(sw==0)
                {
                        LED=0;
                        delay(10);
                        LED=1;
                }
        }
}
void delay(unsigned int n)
{
        TMOD= 0x01; // timer 0 mode 1
        TH0=0xDC;
        TL=0x00;
        TR=1;
        while(TF==0);
        TF=0;
        TR=0;
}

When I compile this code in keil I am getting following errors

Rebuild target 'Target 1'
compiling switch.c...
switch.c(24): error C202: 'TL': undefined identifier
switch.c(25): error C202: 'TR': undefined identifier
switch.c(26): error C202: 'TF': undefined identifier
switch.c(27): error C202: 'TF': undefined identifier
switch.c(28): error C202: 'TR': undefined identifier
Target not created.
Build Time Elapsed:  00:00:00

Any help could greatly appreciated..