Problem with changing cell from Negative number based on User Form

Hi all. I am new to the forum. I have self taught myself VBA over the past couple of weeks but am stuck on this one. Help!?

So with a user form I have created a way to enter data into a budget spreadsheet. This is what I want to do. I want the user form to calculate all numbers as negative EXCEPT when I click the option box that says Deposit. Then I want it to make the number positive. When the data is put into the worksheet, beginning at C26 is a column for deposit. If the option box is checked it is populated with the text deposit. B26 is the amount.

So in short, if C26 says deposit, I want it to make the number positive.
If C26 remains blank, I want it to automatically change the number to a negative number.

Clear as mud?

Thanks for your help I am so confused and am at my wits end.

Pl attach a sample file with dummy data with result required.

I feel like an idiot. I am not sure what a dummy file is? I was googling it, but wasn't sure I would attach what you want. Sorry, I'm new to this.

Would the code work? I am more than happy to submit a dummy file...would you be willing to walk me through it?

Thanks all