Output Value With Sp_executesql Problem

I cannot get my output parameter to output... It comes up as NULL!

I Pass in @NumFound as an OUTPUT Parameter as follows

...@NumFound INT OUTPUT

AS...

Then I build the where clause which I know is working properly because it is used in another sp_executesql statement which is returning the correct results. Then I do this to get a total count of the records found, and I get nothing back...

SET @l_ParamDef = N'@PType nvarChar(50),
@Client nvarChar(50),
@City nvarChar(50),
@ApptDate nvarChar(50),
@OrderDate nvarChar(50),
@Status nvarChar(50),
@AType nvarChar(50),
@Text nvarChar(50),
@PageSize INT,
@l_TotalRecords INT,
@NumFoundOut INT OUTPUT'



SET @l_CountSql = 'SELECT @NumFoundOut = COUNT(*) FROM Orders As o' + @l_Where

EXEC sp_executesql @l_Sql, @l_ParamDef, @PType, @Client, @City, @ApptDate, @OrderDate, @Status, @AType, @Text, @PageSize, @l_TotalRecords, @NumFoundOut = @NumFound OUTPUT

Thank You,

Jason