Unique value validation on custom field

[ebrahim rezaian]

Hello guys 

I have a text field named : PhoneNumber

In create transition i wrote a Scripted (Groovy) Validator to validate that Entered value in PhoneNumber is unique and never created before.

but it doesn't work.

My code :

def x = issue.getAsString("customfield_11109")
def partentkeys= jqlSearch("PhoneNumber~"+"x", 20 ).size()
if(partentkeys==0)
{
return true
}
else
{
return false
}