How to find LCM...?

#include
int find_lcm(int a,int b);

int main()
{
int a,b;
printf("Enter 'a' value:");
scanf("%d",&a);

printf("Enter 'b' value:");
scanf("%d",&b);

printf("\nlcm of %d and %d =%d\n",a,b,find_lcm(a,b));
return 0;
}

int find_lcm(int a, int b)
{
int i;
for(i=1;i<=a*b;i++)
if(i%a = 0 && i%b == 0)
return i;
}