programming problem in 7segment display

[muttusarve]

hi every one..
i'm facing some problem in my projects. i worked it on proteus and i have attached some snaps shot of my project. i'm reading analog i/p from RA2 and display it on 4 7-segments devices. i used 74ls78 bcd to 7 segment decoder and 74ls138 decoder. i've copied my source code too with this. the fig1 shows the intial setup and fig2 shows the during execution of the project.fig3 shows the message what i'm getting when i simulate it in protues.. when i simulate in proteus only one device is active and its always shows zero (0) irrespective of analog input. i want to display the result on 7 segment so please go through the code and let me know if is there any changes have to make in this.
code:

#include<16f877.h>
unsigned int cnt, brk;
char led [3];
unsigned int rem;
void converter (unsigned int z);
void scanled (void);
void main()
{
OPTION_REG=0x80;
PORTA=0;
TRISA=255;
PORTD=0;
TRISD=0;
while(1)
{
cnt=ADC_Read(2);
cnt=cnt*5;
converter (cnt);
scanled ();
}
}
void converter(unsigned int z)
{
led[0]=z/1000;
rem=z%1000;
led[1]=rem/100;
rem=rem%100;
led[2]=rem/10;
led[3]=rem%10;
}
void scanled (void)
{
unsigned char i;
for (i=0;i<4;i++)
{
portd=i;portd=led[i];delay_ms(10);
}
}