Creating & Searching a Record in C

#include<stdio.h>
#include<conio.h> 
struct student
{
int rollno;
char name[15];
int marks;
};
void main()
{
struct student a[50];
int n,reply,srollno,option,i;
clrscr();
do
{
printf("\n 1. Create record");
printf("\n 2. Search record");
printf("\n 3. Exit");
printf("\n\n Select a Valid Option :");
scanf("%d",&option);
switch(option)
{
case 1 :
printf("\nEnter n : ");
scanf("%d",&n);
read(a,n);
break;
case 2 : 
printf("\nEnter srollno : ");
scanf("%d",&srollno);
reply = search(a,n,srollno);
if( reply == -1)
printf("\n Not found");
else
{
printf("\nRoll\tName\tMarks");
printf("\n%d\t%s\t%d",a[reply].rollno,a[reply].name,a[reply].marks);
}
break;
case 3 : exit(0);
} 
}while(1);
}


int read(struct student a[], int n)
{
int i;
printf("\nEnter %d records\n",n);
for(i=0;i < n;i++)
{
printf("\nRoll : "); scanf("%d",&a[i].rollno);
printf("\nName : "); flushall(); scanf("%s",a[i].name);
printf("\nMarks : "); scanf("%d",&a[i].marks);
} 
return;
} 


int search(struct student a[], int n , int srollno)
{
int i;
for(i=0;i < n;i++)
{
if( a[i].rollno == srollno)
return(i);
}
return(-1);
}