propertyChange Event Executes on Form Load

I have the following code on the propertyChange event of a dropdown box and it executes on form load.
I only want it to execute when the selected value changes.
I’m new to Ignition, so any help would be appreciated, Thanks.

if event.propertyName == 'selectedStringValue':
	tank =  '57'
	productNew = event.newValue
	productOld = event.oldValue	
	userName = system.security.getUsername()
	user = system.user.getUser("", userName)
	userid = user.get(user.FirstName) + " " + user.get(user.LastName)
	today = system.date.now()
	todayf = system.date.format(today, "yyyy-MM-dd HH:mm:ss")
	comp = system.net.getHostName()
	system.db.runUpdateQuery("INSERT INTO TankHistory(TankNumber, TankProductOld, TankProductNew, t_Userid, t_stamp, ClientCPU) " + "VALUES ('%s', '%s', '%s', '%s', '%s', '%s')" %(tank, productOld, productNew, userid, todayf, comp))

Try changing that to:
if event.propertyName == 'selectedStringValue' and event.source.componentRunning:

Thank You, it looks like that worked…

For an explanation: The ‘selectedStringValue’ is (probably) changing on your component more than once because there’s an initial set of the value as the component is created, then another as the last saved value in the designer is applied, and then a third when any binding(s) that affect the component are evaluated. The componentRunning flag is only set when all of those things have been completed.