help for the program for water tank

i have put one FUNCTION (Display) in the code's
but still not functional

is there any way by which we can convert BCD to DEC code's and can be printed out as output

I know its wrong please help me to make it right
thanks
[ the CODE's is for 'C' not for 'ARDUINO' ]

#include<stdio.h>
#include<conio.h>
void display(int z) // function declared Display(int z)
int main(void)
{
     int a,b,c,d;
     int x0,x1,x2,x3,x4,x5,x6,x7,x8,x9,x10,x11,x12,x13,x14,x15;
     x0=00;
     x1=10;
     x2=20;
     x3=25;
     x4=30;
     x5=40;
     x6=50;
     x7=60;
     x8=70;
     x9=75;
     x10=80;
     x11=90;
     x12=100;
     x13=0;
     x14=0;
     x15=0;
     printf("Enter the Val of A,B,C,D\n");
     scanf("%d,%d,%d,%d",&a,&b,&c,&d);
     printf("Val of a,b,c,d,%d,%d,%d,%d",a,b,c,d );
     display(int z)
     getch();
     }


{

    void display(int z) //Function CALLED

{
    if(a==0&&b==0&&c==0&&d==0)
    printf("%a,%b,%c,%d is 00% EMPTY",x0);//0000=00
    }
{
    if(a==0&&b==0&&c==0&&d==1)
    printf("%a,%b,%c,%d is 10%",x1);//0001=01
    }
{
    if(a==0&&b==0&&c==1&&d==0)
    printf("%a,%b,%c,%d is 20%",x2);//0010=02
    }
{
    if(a==0&&b==0&&c==1&&d==1)
    printf("%a,%b,%c,%d is 25%",x3);//0011=03
    }
{
    if(a==0&&b==1&&c==0&&d==0)
    printf("%a,%b,%c,%d is 30%",x4);//0100=04
    }
{
    if(a==0&&b==1&&c==0&&d==1)
    printf("%a,%b,%c,%d is 40%".x5);//0101=05
    }
{
    if(a==0&&b==1&&c==1&&d==0)
    printf("%a,%b,%c,%d is 50%",x6 HALF);//0110=06
    }
{
    if(a==0&&b==1&&c==1&&d==1)
    printf("%a,%b,%c,%d is 60%",x7);//0111=07
    }
{
    if(a==1&&b==0&&c==0&&d==0)
    printf("%a,%b,%c,%d is 70%",x8);//1000=08
    }
{
    if(a==1&&b==0&&c==0&&d==1)
    printf("%a,%b,%c,%d is 75%",x9);//1001=09
    }
{
    if(a==1&&b==0&&c==1&&d==0)
    printf("%a,%b,%c,%d is 80%",x10);//1010=10
    }
{
    if(a==1&&b==0&&c==1&&d==1)
    printf("%a,%b,%c,%d is 90%",x11);//1011=11
    }
{
    if(a==1&&b==1&&c==0&&d==0)
    printf("%a,%b,%c,%d is 100% FULL",x12);//1100=12
    }
{
    if(a==1&&b==1&&c==0&&d==1)
    printf("%a,%b,%c,%d is 100% ALARM",x13);//1101=13
    }
{
    if(a==1&&b==1&&c==1&&d==0)
    printf("%a,%b,%c,%d is xXx",x14 );//1110=14
    }
{
    else(a==1&&b==1&&c==1&&d==1)
    printf("%a,%b,%c,%d is XxX",x15);//1111=15
    }

}