##### Define > Custom Field Type > Custom Field Type Properties

# ASPX Form Tab

The ASPX Form Process code takes what is submitted by the form and returns the session variable with its new value.

The ASPX Form Code is C# code that takes in the field identifier as an argument and returns a new value for the session variable. This is an example of code that might be entered in the ASPX Form tab.

<script language="c#" runat="server">

String CFTFP_My_New_Type(String field_identifier)

{

String formField = field_identifier + "val1";

String addToEnd = getProp(field_identifier, "add_to_end");

return Request.Params.Get(formField) + addToEnd;

}

</script>

This function takes the form value and adds the value of the add_to_end property to the end of the session variable.

Properties defined in the Properties tab can be referenced in the ASPX Form Processing code. To do this, the property is referenced by the getProp() function call, as seen by the add_to_end property above in the example code.