Conversion of Uppercase to Lowercase in C

 #include<stdio.h> 
#include<conio.h> 
void main() 
{ 
char ch; 
clrscr(); 
printf("Enter a Character"); 
scanf("%c",&ch); 
if(ch>=65 && ch<=90) 
ch=ch+32; 
printf("Upper Case =%c",ch); 
getch(); 
}