Radio Button

Hi Narmada , can you please tell what exactly is happening? Are you getting any error?

Could not display interface. Please check definition and inputs.
Interface Definition: Expression evaluation error at function a!formLayout [line 125]: Invalid index: Cannot index property 'Challan' of type Text into type List of Text String

I have taken one radio button named payment type & first button named online second button named Challan when i want to click on challan button i want to display below selection layout

I am attaching a sample code to achieve the same. Refer this and share your code if you are having any trouble after this.

  a!formLayout(
  label: "",
  contents: {
    a!sectionLayout(
      label: "",
      contents: {
        a!radioButtonField(
          label: "Payment Type",
          labelPosition: "ABOVE",
          choiceLabels: {"Online", "Challan"},
          choiceValues: {1, 2},
          value:ri!val,
          saveInto:ri!val,
          choiceLayout: "STACKED",
          validations: {}
        )
        
      }
    ),
   if(ri!val=2,
     a!columnsLayout(
      columns: {
        a!columnLayout(
          contents: {
            a!sectionLayout(
              label: "Lorem Ipsum",
              contents: {
                a!textField(
                  label: "Lorem Ipsum",
                  labelPosition: "ABOVE",
                  saveInto: {},
                  refreshAfter: "UNFOCUS",
                  validations: {}
                )
              }
            )
          }
        ),
        a!columnLayout(
          contents: {
            a!sectionLayout(
              label: "Lorem Ipsum",
              contents: {
                a!textField(
                  label: "Lorem Ipsum",
                  labelPosition: "ABOVE",
                  saveInto: {},
                  refreshAfter: "UNFOCUS",
                  validations: {}
                )
              }
            )
          }
        )
      }
    ),{})
  }
)

I am attaching a sample code to achieve the same. Refer this and share your code if you are having any trouble after this.

  a!formLayout(
  label: "",
  contents: {
    a!sectionLayout(
      label: "",
      contents: {
        a!radioButtonField(
          label: "Payment Type",
          labelPosition: "ABOVE",
          choiceLabels: {"Online", "Challan"},
          choiceValues: {1, 2},
          value:ri!val,
          saveInto:ri!val,
          choiceLayout: "STACKED",
          validations: {}
        )
        
      }
    ),
   if(ri!val=2,
     a!columnsLayout(
      columns: {
        a!columnLayout(
          contents: {
            a!sectionLayout(
              label: "Lorem Ipsum",
              contents: {
                a!textField(
                  label: "Lorem Ipsum",
                  labelPosition: "ABOVE",
                  saveInto: {},
                  refreshAfter: "UNFOCUS",
                  validations: {}
                )
              }
            )
          }
        ),
        a!columnLayout(
          contents: {
            a!sectionLayout(
              label: "Lorem Ipsum",
              contents: {
                a!textField(
                  label: "Lorem Ipsum",
                  labelPosition: "ABOVE",
                  saveInto: {},
                  refreshAfter: "UNFOCUS",
                  validations: {}
                )
              }
            )
          }
        )
      }
    ),{})
  }
)