adc0804 and 3 7seg display

hello everyone
i write a simple program using c language for read analog value from adc0804 then convert that value to three decimal number and then display them on 3 seven_seg but when i compile the program using keil ide i got some error ( like 'multiple public definition ')
can anyone help me with it .

#include <REGX51.H>
sbit cs   = P3^7 ;
sbit WRIT	= P3^5 ;
sbit READ	= P3^6 ;
sbit inter= P3^4 ;
#define adc_port  P1 
#define seg_port  P0 

char ones,tens,hunds,digital_value,rfd;
int table[16]={0x40,0x79,0x24,0x30,0x19,0x12,0x02,0x78,0x00,0x10,0x08,0x03,0x46,0x21,0x06,0x0e};
void conv();
void read_adc();
void delay_us(int);
void delay_ms(int);
void delay_sec( char);
void div23dig(char);
void disp ( char , char, char );
void main(){
							
							adc_port = 0xff	;		//init adc_Port as input
									P0 = 0X0			;//init p0 as output
									P3= 0x10		;	//init p3.4 as input
								while(1){
									
									
										conv();
										read_adc();
										div23dig(digital_value);
									  disp(ones,tens,hunds);
										delay_sec(1);
									 
										
												}
            }

void conv()
	{
		cs=0;
		WRIT=0;
		WRIT=1;
		cs=1;
		while(inter);
	}

void read_adc()
	{
			cs=0;
			READ=0;
			digital_value=adc_port;
			READ=1;
			cs=1;
  }

void delay_us( int us_count)
 {
    while(us_count!=0)
      {
         us_count--;
       }
   }
void delay_ms( int ms_count)
 {
        while(ms_count!=0)
         {
            delay_us(112);   /*delay_us is called to generate 1ms delay*/
             ms_count--;
            }
   }
void delay_sec( char sec_count)
 {

     while(sec_count!=0)
      {
         delay_ms(1000);    /*delay_ms is called to generate 1sec delay*/
         sec_count--;
        }
 }
void div23dig(char x )
 { 
		hunds= digital_value/100 ;
		rfd = digital_value%100 ;
	  tens = rfd/10;
		ones = rfd%10;
	
 }
void disp ( char x , char y ,char z )
 {  char i; 
		i = table[ones] ;
	  seg_port = i ;
	  P2=P2|1;
	  delay_ms(16);
		P2=P2&254;
	  i=table[tens];
	 seg_port=i;
	  P2=P2|2;
		delay_ms(16);
	   P2=P2&253;
		i= table[hunds];
	  seg_port=i;
	  P2=P2|4;
		delay_ms(16);
	  P2=P2&251;
 
 }

"when i compile the program using keil ide i got some error
( like 'multiple public definition ')"

When asking for help, giving the exact error message is important.
It is better to zip and post your full code,
as copying off the web page is not 100% successful.

I tried your code and got unused variables warnings for call
"void disp ( char x , char y ,char z )"
x,y and z are not used in the procedure.

I notice you declared it as
"void disp ( char , char, char );" without naming the variables.
That may be legal, but makes it harder to spot errors, as in the case above.

It will be easier to help if you can post the complete error message with line number. So we know which line is generating the error.
By the way, it's better to define "table" as const since you're not going to change it but just use it as a reference for digits.

actually i solve this problem , and it was just test for my project which is"power meter"
so i could measure the ac voltage and display it on 3 7-seg , and then moved to measure current using CT 1000:1 and it worked very good with some error , but when i tried to merge current and voltage together i used tow adc0804( i could to use adc0808 but the time was very short to do that ) and connect it with same PORT on micro , i will attach the schematic and the code to understand what i'm trying to say so maybe you can help me .

these are my schematic and c source file , and i hope to help me because i tried to solve it for two weeks and there is no progress at all

https://drive.google.com/open?id=0B_IGcFftMx3fYV9VTmw5dkp2Q2s

I don't think the 0804 works as it should in Proteus.
I ended up greatly simplifying your design to get it working.
The good news is that you have a working start point.
Use the virtual serial port in Proteus to print messages to help
with debugging.