Help with an SQL Expression - Return field value where Datetime is Min or First datetime

Hello,

I'm extracting results for a patient population.

I have 6 SQL expressions that pull back the first date for specific procedures or Medications being ordered.

These Expressions work perfect - One of the expressions return the first time a lab was ordered.

I'm using SQL that return

Min(OrderDatetime)

From OrderTable

Where

LABCode = XXX

I've now been ask to return the value of this lab result.

Question: How do I write an SQL expression that return the Lab value of the Min(OrderDatetime)

Example Data

PATID* LABID * OrderDatetime * ResultValue

Pat1*133 * 12/12/2013 11:00:pm * 77

Pat1*145 * 12/12/2013 11:45:pm * 45

Pat1*147 * 12/13/2013 12:10:AM * 78

I was to return 77

Thanks

Steve