By using the Post QueryString, I was able to get it working!! All I had to do was check the box.
This is an example of what I wrote in my script:
def firstName = context.expand( '${DataSource POST PD#FirstName}' )
def baseString = startDate.format("yyyy_MM_dd'T'HH_mm_ss_SSS")
if (partyName.compareToIgnoreCase("Random") == 0)
{
firstName = "First" + baseString
testRunner.testCase.setPropertyValue( "FirstName", firstName )
}
Then I used ${#TestCase#FirstName} for the value of first_name in the POST step. The value in the REST request was first_name=First2013_04_04T16_24_04_779.
Success for my first POST request! Thanks so much for your help along the way.
Trish