IF Statements

[#1]

I am trying to convert the following case statement into Qlikview statement. Please let me know where my mistake is:

SQL Case Statement:

case ANSWER_TEXT is null

then STRING_VALUE

when STRING_VALUE is null

then TEXT_VALUE

when TEXT_VALUE is null

then DATE_VALUE

when DATE_VALUE is null

then NUMBER_VALUE

ELSE answer_text

Qlikview If Statement:

= IF(IsNull(ANSWER_TEXT) ,(IF(IsNull(STRING_VALUE), IF(isnull(TEXT_VALUE), IF(isnull(DATE_VALUE), NUMBER_VALUE),TEXT_VALUE), STRING_VALUE),ANSWER_TEXT)

[vishsaggi]

May be this?

= IF(Len(Trim(ANSWER_TEXT))= 0, STRINT_VALUE,

     IF(Len(Trim(STRING_VALUE)) = 0, TEXT_VALUE,

        IF(Len(Trim(TEXT_VALUE)) = 0, DATE_VALUE,

           IF(Len(Trim(DATE_VALUE))= 0, NUMBER_VALUE, ANSWER_TEXT))))

[m_woolf]

= IF(IsNull(ANSWER_TEXT), STRING_VALUE,

     IF(IsNull(STRING_VALUE), TEXT_VALUE,

          IF(isnull(TEXT_VALUE), DATE_VALUE,

               IF(isnull(DATE_VALUE), NUMBER_VALUE,ANSWER_TEXT)

            )

        )

     )