i have fixed all the mistakes poimted but still code not working
My new modified codes are:

//transmit program
#include<reg51.h>

void Serial_Init(void)
{
SCON=0x50;
EA=1;
ES=1;
TMOD=0x20;
TH1=0xE6;
TR1=1;
}

void Transmit_Char(unsigned char c)
{
while(!TI){} //Waits until transmit
TI=0;
SBUF=c;
}
void main(void)
{
unsigned char tchar;

P1=0x00;
P3=0x00;

Serial_Init();

while(1)
{
tchar=P1;
Transmit_Char(tchar);
}
}


//receive program

#include<H:C51AINCLUDEreg51.h>

void Serial_Init(void)
{
SCON=0x50;
EA=1;
ES=1;
TMOD=0x20;
TH1=0xE6;
TR1=1;
}

void call() interrupt 4
{
if(RI)
{
P1=SBUF;
RI=0;
}
if (TI)
TI=0;
}

void main(void)
{
Serial_Init();
while(1){}
}