AVR code problems with USART

#include <avr/io.h>
#include <util/delay.h>		//Max delay: 262.14 ms / F_CPU in MHz

//#define F_CPU 4000000// Clock Speed
//#define BAUD 9600
#define MYUBRR 24//F_CPU/16/BAUD-1

///////////////////////////////////////////////USART Init/////////////////////////////////////////////////////////
void USART_Init( unsigned int ubrr)
{
/* Set baud rate */
UCSR0A=(1<<U2X0);		//Divisor in BAUD set to 8. USX0=0 divisor=16, USX0=1 divisor=8
UBRR0H = (unsigned char)(ubrr>>8);
UBRR0L = (unsigned char)ubrr;
/* Enable receiver and transmitter */
UCSR0B = (1<<RXEN0)|(1<<TXEN0);
/* Set frame format: 8data, 1stop bit */
UCSR0C = (0<<USBS0)|(3<<UCSZ00);
}
///////////////////////////////////////////////USART Transmit/////////////////////////////////////////////////////
void USART_Transmit( unsigned char data )
{
PORTD|=(1<<PD6);	//RS485==Transmit
_delay_ms(1);
/* Wait for empty transmit buffer */
while ( !( UCSR0A & (1<<UDRE0)) );
/* Put data into buffer, sends the data */

UDR0 = data;
//_delay_ms(1);
PORTD&=~(1<<PD6);	//PE6: RS485==Receive
}

///////////////////////////////////////////////USART Recieve//////////////////////////////////////////////////////
unsigned char USART_Receive( void )
{
/* Wait for data to be received */
while ( !(UCSR0A & (1<<RXC0)) );

/* Get and return received data from buffer */
return UDR0;
}

///////////////////////////////////////////////Main///////////////////////////////////////////////////////////////
int main(void)
{
   USART_Init(MYUBRR);
   
   DDRA=0xFF;		//PORTA output. LEDs connected to this port
   DDRD=0xFF;		//PORTF output
   DDRC=0x00;		//PORTC input 
   
   PORTC=0xFF;		//Set PORTC to 'High'
            
   PORTA=0xFF;		//Turn OFF all LEDs
   PORTD&=~(1<<PD6);	//PE6: Receive
   
   unsigned char x=0;
      
   while(1)
   {
	   
	   if ((PINC & 0x01)==0)
	   { 
		   PORTA=0x00;
		   
		   USART_Transmit(0x54);		   
	   }	   
	   
	   if ((PINC & 0x02)==0)
	   {
		   PORTA=USART_Receive();
	   }
	   
	   
   } 
}

unsigned char USART_Receive( void )
{
    volatile uint16_t counter=0;

    /* Wait for data to be received */
    while ( !(UCSR0A & (1<<RXC0)) ) {
        counter++;
        if (counter==20000) break; //change according to needed delay

    }

    /* Get and return received data from buffer */
      if (counter != 20000) return UDR0;
	  else return 255; // all leds off

}

unsigned char USART_Receive( void )
{
[B]/* Wait for data to be received */[/B]
while ( !(UCSR0A & (1<<RXC0)) );

/* Get and return received data from buffer */
return UDR0;
}

void USART_Transmit( unsigned char data ) {

    /* Wait for empty transmit buffer */
    while ( !( UCSR0A & (1<<UDRE0)) );
    
	/* Put data into buffer, sends the data */
    UDR0 = data;
}

unsigned char USART_Receive( void ) {
    
	/* Wait for data to be received */
    while ( !(UCSR0A & (1<<RXC0)) );

    /* Get and return received data from buffer */
    return UDR0;
}

#pragma vector = USART1_RX_vect
__interrupt void USART1_Rx_ISR (void)
{ 
  USART1RxInterruptCallback(); 
}
  
#pragma vector = USART1_TX_vect 
__interrupt void USART1_Tx_ISR (void)
{ 
  USART1TxInterruptCallback(); 
}