Get the current value index. Radio button groups and check box fields can have multiple widgets having the same button value.For check box fields and radio buttons without f_RadiosInUnison set, specifying the selected button by value string is not possible in that case.A 0 - based value index can be used to find out which button is selected or to select a button. Radio button groups and check box fields need not use a value index; in fact, they usually don't. SignDocDocument.addField() and SignDocDocument.setField() update the value index if the value of a radio button group or check box field is selected by string(ie, setValue()) and the field has ambiguous button names. The "Off" value never has a value index.

public int getValueIndex()