Javascript to return Yes/No based on autolookup field value

Hello,

I'm trying to write some javascript that will be run when an eform autolookup control is run. Specifically, I would like a field to be set to "Yes" if the autolookup fills in a numeric value into a second field called "ListIDtextbox". If the autolookup does not fill in a value then I would like the script to fill in "No" in the field.

Here's what I have so far which functions to tell me the autolookup has run successfully. However, I believe I need to add an IF statement to this to also check the field for a value before it. The field name of the field I would like to check for the numeric value is called "ListIDtextbox". The Field where the Yes/No would appear is "ExistingJobDescriptionfound". Currently, the script puts 'Yes" in "ExistingJobDescriptionfound" when the autolookup runs regardless of if there is a value in "ListIDtextbox" Thanks for any pointers/examples you can provide on how to accomplish this.

function DescriptionFound()
{
  var option = {fieldId : "ExistingJobDescriptionfound", value : "Yes"} ;
  eFormHelper.setFieldValue(option, function(result)
{
if (result.isSuccess) //check if is success
    {
    console.log(result.data); //logs the data holds empty object
    }
  else
    {
    console.log(result.error); //logs the error
    }
});}