To everyone that replied...Thank you. I greatly appreciate it. Got it figured out. Pasting the final code below.
private static void OrderDtl_BeforeFieldChange(object sender, DataColumnChangeEventArgs args)
{
switch (args.Column.ColumnName)
{
case "PartNum":
Epicor.Mfg.Core.Session objSession = oTrans.Session as Epicor.Mfg.Core.Session;
Epicor.Mfg.BO.Part adpPart = new Epicor.Mfg.BO.Part(objSession.ConnectionPool);
Epicor.Mfg.BO.PartDataSet dsPart = new Epicor.Mfg.BO.PartDataSet();
dsPart = adpPart.GetByID(args.ProposedValue.ToString());
if (dsPart.Tables[0].Rows.Count > 0) {
if (dsPart.Tables[0].Rows[0]["Inactive"].ToString() == "True") {
args.ProposedValue = "";
}
}
break;
}
}