Interruption with button counter

[cheverecamachidoche 13]

Hello guys im making a program that count the number of button pushes with a interruption, every time that the button is pushed a servomotor get a position of 4 positions availables, the problem is when the servomotor get the last position and then I push the button one more time the servomotor is in the same last position so I would like that when I push the button the servomotor start again in the first position, I tried with return and break but it doesnt work, please any advice?

here the interruption:

#pragma vector=PORT2_VECTOR
__interrupt void Port2_ISR(void)
{

if(!(PxIFG & GDO0_PIN));
if(PxIFG & GDO0_PIN);
{ 
conta++;
}

if (conta==1)
{
Firstposition();
}
if (conta ==2)
{
Secondposition();
}
if (conta ==3)
{
Thirdposition();
}
if (conta ==4)
{
Quarterposition();
}
else;

// I tried break and return like this:
//break;
//return;

   PxIFG &= ~GDO0_PIN;      
}

[oPossum 1,083]

   switch(conta) {
       case 1:                 //
       default:                // All other case values
           conta = 1;          // Reset count
           Firstposition();
           break;
       case 2:
           Secondposition();
           break;
       case 3:
           Thirdposition();
           break;
       case 4:
           Quarterposition();
           break;
   }

[cheverecamachidoche 13]

Thanks Opossum now is working