I seem to get an error when running one of the go challenges

Ok so where's the question. I believe my code is working but I get an error.

challenge:

In the sales package, define an exported CalculateTax function. CalculateTax should accept a float64 parameter representing a sales total, and a second float64 parameter representing a tax rate. The function should multiply the sales total by the tax rate, and return the result as a float64 value. So, for example, sales.CalculateTax(100.0, 0.08) should return approximately 8.0. (Very small floating-point math errors are OK.)

Error: Bummer! # command-line-arguments ./report.go:9: multiple-value sales.CalculateTax() in single-value context

My code description:
The error appears on "func CalculateTax(salesTotal, taxRate float64) (float64, error) {"

package sales

import ( "fmt" )

func CalculateTax(salesTotal, taxRate float64) (float64, error) { result := salesTotal * taxRate // Check the value if result <= 0 { return result, fmt.Errorf("Please check your sales total %f and tax rate %f", salesTotal, taxRate) } return result, nil }

Now I believe the treehouse code check won't accept parameters since the error string calls sales.CalculateTax(). Not a 100% sure but wanted to check with you all.

package sales

import (
  "fmt"
 )

func CalculateTax(salesTotal, taxRate float64) (float64, error) {
  result := salesTotal * taxRate
  // Check the value 
  if result <= 0 {
    return result, fmt.Errorf("Please check your sales total %f and tax rate %f", salesTotal, taxRate)
  }
  return result, nil
}