Grading Program -Using C++ Language

#include<stdio.h>
#include<conio.h>
void main()
{
 int marks;
 clrscr();
 printf("Enter ur Marks");
 scanf("%d",&marks);
 if(marks>90)
 printf("Your grade is A");
 else if(marks>=80)
 printf("ur grade is B");
 else if(marks>=70)
 printf("ur grade is C");
 else if(marks>=60)
 printf("ur grade is D");
 else if(marks>=50)
 printf("ur grade is E");
 else if(marks<=50)
 printf("ur grde is F");
 getch();
 }