Update Value using Stored Procedure

[bLuEmEzzy]

Please help me.. i am stuck with this one... i have a a field(TotalAmount) in Table(Deposits)
when i run this stored proc
when i put

@TotalAmount = 5000.00
the table became 5.00
i tried everything, still not working properly... thank u :)

ALTER PROCEDURE [General].[EditTable]
	-- Add the parameters for the stored procedure here
		@TotalAmount VarChar,
		@ID varChar	

AS
BEGIN
	-- SET NOCOUNT ON added to prevent extra result sets from
	-- interfering with SELECT statements.
	SET NOCOUNT ON;
				    -- Insert statements for procedure here
	BEGIN TRY
		DECLARE @Query NVarChar(max),
			  @ParamDefinition NvarChar(2000)
		
	BEGIN TRANSACTION 
			BEGIN
			
				SELECT @Query = 'UPDATE Deposits SET TotalAmount = '+@TotalAmount +'  WHERE ID = '+@ID 
				SELECT @ParamDefinition = '@TotalAmount VarChar,@ID VarChar'
				EXECUTE SP_EXECUTESQL @Query, @ParamDefinition, @TotalAmount, @ID