Stored Procedures, msSQL

[invitro]

I figured I'd start a new thread for this
Ok, these things are frustrating the hell outa me! grrr...

ok, why would this not work

CREATE PROCEDURE sp_getTableWhere 
	
	@vTable varchar(20),
	@vcharValue1 varchar(20),
	@vcharValue2 varchar(20)
AS

	SELECT * FROM @vTable
	WHERE @vcharValue1 = @vcharValue2

Sais I need to declare @vTable

What im trying to do is select all records from a certain table by Value 1 and Value 2 where
Value1 is the Column, and Value 2 is the matching value for that column.



Problem #2)
I wrote this simple function to see if a user exists

CREATE PROCEDURE sp_isValidLogin 

	@charUsername varchar(50),
	@charPHash varchar(50)

	AS
	if(DATALENGTH(@charUsername) = 0 AND DATALENGTH(@charPHash) = 0)
		RETURN 0

		if exists(SELECT * FROM tblUser
	
			WHERE @charUsername = charUsername
	
		 AND
	
			@charPHash = charPHash)
			return 1
		else
			return 0
GO

When you call a return, does it terminate the stored procedure like a javascript or c++ statement would? Because it keeps giving me this message if @charUsername and @charHash are empty

[Microsoft][ODBC SQL Server Driver][SQL Server]Cannot use empty object or column names. Use a single space if necessary.

If i do pass in the value, and it does exist... SQL sais: Missing Default Property. What, huh? I thought returning 0 or 1 is enough?

Arghhhhh... i hate when things dont work