Error generating 1 sec delay using timers in PIC32

I finally designed a logic using timers which is giving me 1ms delay:

#define FCY 72000000L
#define FPB 36000000L
#pragma config POSCMOD=XT, FNOSC=PRIPLL
#pragma config FPLLIDIV=DIV_2, FPLLMUL=MUL_18, FPLLODIV=DIV_1
#pragma config FPBDIV=DIV_2, FWDTEN=OFF, CP=OFF, BWP=OFF

void Delayms( unsigned t)
{
   T1CON = 0x8000; 
   while (t--)
   { 
      TMR1 = 0;
       while (TMR1 < FPB/1000);
   }
}