Designation of the Employee according to salary


#include<iostream.h>
#include<conio.h>
void main()
{
float sal;
clrscr();
cout<<"Enter the salary of employee:";
cin>>sal;
if (sal<20000)
{
if(sal<=10000)
cout<<"clerk"<<endl;
else
cout<<"Assistant manager:"<<endl;
}
else
cout<<"Manager"<<endl;


Is this program code right, if it is can you explain why ther is sal<20000 and sal<=10000

and also how can Assitant manager and Manage can be diffrentiated