Get Date Field to autofill when digital signature is applied to form.

Hello,

I have a travel form which our company uses - I have two digital signature fields and two date fields.

I would like the date field to auto fill with current date when signature is applied.

I have one semi working on Signature1 and Date Prepared Fields..

"Date Prepared" is running this javascript as soon as Signature 1 is applied

// JavaScript code to add the date at signing time

    var currentTime = new Date()

    var month = currentTime.getMonth() + 1

    var day = currentTime.getDate()

    var year = currentTime.getFullYear()

    var signingTime = month +"/"+day+"/"+year  //Modify into your preferred format

    var f = this.getField("Date Prepared");  //Modify the field name as necessary

    f.value = signingTime

Question is how can I assign particular date field to particular digital signature , so the date work auto fill when the digital signature is applied .

Thanks

Tom