ending lines

I need to output the following to a screen:

SUN MON TUE WED THU FRI SAT
1 2 3 4
5 6 7 8 9 10 11
12 13 14 15 16 17 18
19 20 21 22 23 24 25
26 27 28 29 30 31

this is my code so far:

#include<stdio.h>
#include<conio.h>

main()
{

int first_day,
days_in_month;


printf("Enter day on which the 1st falls 1 = Sunday 2 = Monday etc : ");
scanf("%d", &first_day);

printf("How many days the month? : ");
scanf("%d", &days_in_month);

printf("\n SUN MON TUE WED THU FRI SAT\n");

int columns = 1;


while (columns <= first_day -1)
{
printf(" ");
columns += 1;
}

int day_index = 1;

while (day_index <= days_in_month)
{
if (columns = 7)
{
printf("%4d", day_index);
columns = 1;
printf("\n");
}
else
{
printf("%d", day_index);
columns += 1;
}
day_index += 1;
}
getch();

}
It's not ending the line as I need it to. Any suggestions?



:confused:

Code:

---

#include<stdio.h>
#include<conio.h>
int main() {
    int first_day, days_in_month;
    int columns = 1;
    int day_index = 1;      // should be declared here - this is C, not C++
    printf( "Enter day on which the 1st falls 1 = Sunday 2 = Monday etc : " );
    scanf( "%d", &first_day );
    printf( "How many days the month? : " );
    scanf( "%d", &days_in_month );
    printf( "\n SUN MON TUE WED THU FRI SAT\n" );
    while(columns <= first_day -1) {
        printf( "    " );
        columns += 1;
    }
    while(day_index <= days_in_month) {
        if(columns == 7)  // should be ==
            {
            printf( "%4d", day_index );
            columns = 1;
            printf( "\n" );
        } else {
            printf( "%4d", day_index );  // print this in a 4 width as well
            columns += 1;
        }
        day_index += 1;
    }
    getch( );
}

---