Vowel Counter:

there are 4 vowels in this text.

Is this a prime number

Change Celsius to Fahrenheit or vice versa

Pseudo Function

I would like to make a calculator. I will make a text box and a button for each simple operator (+, -, *, /, and =). When I click the button, the function takes the value in the text box (if it's blank, it's 0) and prepares to execute the operator for the next value. The function makes the text box blank, ready for your next input. You put in the value, you can either keep going and add another simple operator, or click that "=" sign and get your answer (also in the text box).