Hi Santhosh,
While calling the form you got this exception because the parameter in form is different and the parameter that you passing to form is different. So check with the datatype of the attribute that you passing.
Ex for causing error may be like this:
DATA lv_str TYPE string.
PERFORM test USING lv_str.
FORM test im_str TYPE c.
***
ENDFORM.
Here datatype of lv_str and im_str is different. So here you get exception.
