I am developing web app using C#. I want to replace multiple spaces with single space in between string. I tried with normal string replace function, but it was not helpful. It is possible with Regular Expression, but I don't have clear idea about that. Please provide a example code for the following string:

Actual String:

```
Have       a   Nice              Day !  !!

```

Needed:

```
Have a Nice Day !!!

```