Curious about removing parentheses in CustomValidator's ClientValidationFunction property?

I'm a beginner in asp.net. I tried the `CustomValidator` and put `my_fun()` Javascript function into the `ClientValidationFunction` property. I get that error :

> Microsoft JScript runtime error: Object expected


But when i remove the parentheses i get no errors at all.

Why does that happen ?

I think what's happening is: when you put the name of the function without parentheses, you are putting in a reference to a function *object*. You are indicating which function should be called.

When you put in the function name with parentheses, you are *calling* the function. You are indicating that the function to be called should be the *result* of the function specified.

If your function doesn't return anything, the code that attempts to call the validation function will have nothing to call, and there will be an error.