Script Fields Help - Due Date Changes based on Priority Field

[Elif Alverson]

Hello, 

I am trying to automate due dates based on the priority of the tickets based on a issue type. 

This is what I would like to do; 

If high priory is selected, enter 7 days from today in a due date field.

If medium priory is selected, enter 30 days from today in a due date field.

If low priory is selected, enter 90 days from today  in a due date field.

I have tried to use this one below for script runner - behaviors , but it does not work.

def dueDateField = getFieldByName("Due Date")
def Sev = getFieldByName("Priority").value

def dateToSet

if (Sev == "Critical") {
dateToSet = new Date() + 7
} else if (Sev == "Major") {
dateToSet = new Date() + 30
} else if (Sev == "Minor") {
dateToSet = new Date() + 90
}

dueDateField.setFormValue(dateToSet.format("dd/MMM/yy"))

Any suggestions and help will be appreciated. 

Thank you!