Drop-Down List stored value error in textfield (wordnum)

I am having trouble with the Drop-Down List as the selected value must be expressed in word.

Please be guided by the images below:

Amount Deducted - Drop-down list with values in numerals. User entered

Amount in words - Textfield. Calculated to the get the value of Amount Deducted express into words using this script:

if (not (form1.#subform.AmoundDeduction").isNull) then   $ = Concat( Replace( Replace( Replace( Replace( Upper ( WordNum("form1.#subform.AmoundDeduction"), 2) ), "DOLLARS", "PESOS" ), "DOLLAR", "PESO" ), "CENTS", "CENTAVOS" ), "CENT","CENT"), " ONLY" )
else   $ = "" 
endif

Expected Output:

Thank you in anticipation of your positive response.