already defined of datatype 'BIGINT' but trying to update 'DECIMAL' datatype

already defined of datatype 'BIGINT' but trying to update 'DECIMAL' datatype

I am trying to add in a simple piece of code but I keep getting this error

Variable 'a14_current' is already defined of datatype 'BIGINT' but trying to update 'DECIMAL' datatype

a14_current is a decimal field
a12_allotted is a decimal field

  2. if (input.template08  ==  "01-Preflight")
  3. {
  4.     a14_current = input.a12_allotted * 0.6;
  5. }