$($This must be done in C sharpe Programming$)$ In this exercise, you$$ll create a form that accepts an integer from the user and then calculates

the factorial of that integer.

The factorial of an integer is that integer multiplied by every positive integer less than itself.

A factorial number is identified by an exclamation point following the number. Here$$s how

you calculate the factorial of the numbers $1$ through $5$:

$1!=1$ which equals $1$

$2!=2*1$ which equals $2$

$3!=3*2*1$ which equals $6$

$4!=4*3*2*1$ which equals $24$

$5!=5*4*3*2*1$ which equals $120$

To be able to store the large integer values for the factorial, this app can$$t use the Int$32$ data

type.

$1.$ Start a new project named Factorial in the ExtraStarts$\backslash$Ch$05$ directory.

$2.$ Add labels, text boxes, and buttons to the default form and set the properties of the form

and its controls so they appear as shown above. When the user presses the Enter key, the

Click event of the Calculate button should fire. When the user presses the Esc key, the

Click event of the Exit button should fire.

$3.$ Create an event handler for the Click event of the Calculate button. This event handler

should get the number the user enters, calculate the factorial of that number, display the

factorial with commas but no decimal places, and move the focus to the Number text box.

It should return an accurate value for integers from $1$ to $20.($The factorial of the number

$20$ is shown in the form above.$)$

$4.$ Create an event handler for the Click event of the Exit button that closes the form.

$5.$ Test the app to be sure it works correctly.