Wierd Behavior Of SQL Server While Executing A SP

Hi Friends,

I am struggling with creating a simple stored procedure, I want to take max(timekey) out in one variable @Val in a dynamic SQL statement as below in SP. When I create this SP, it creates successfully but when I run it I get error

Select @Val=MAX(TimeKey) FROM ABC

Msg 137, Level 15, State 1, Line 1

Must declare the scalar variable "@Val".

Can someone help me in understanding this wierd behavior? And how to get rid of this. Table and SP scripts are as below

CREATE TABLE ABC (TimeKey int, Data_Val int)

CREATE Procedure MAXVal(@Table_Name Varchar(30))

AS

BEGIN

DECLARE @Val INT,

@SQL Varchar(100)

SET @SQL='Select @Val=MAX(TimeKey) FROM '+''+@Table_Name+''



EXECUTE (@SQL)

END


Thanks,
Kul