dropdown fill row from other field

What am I doing wrong;

dropdown fill row from other field

var source = this.getField("SCP");

var myList = { "First Item":  { WMs1E_1: 15, MSI1_1: 12, MSL1_1: 24, MSE1_1: 50, MSES1_1_Hid: source.value, MSLd1_1: 1},

"second Item":  { WMs1E_1: 50, MSI1_1: 24, MSL1_1: 48, MSE1_1: 250, MSES1_1_Hid: 3, MSLd1_1: 4}};

I tried with source, "source" and ["source"] and source.value

do I do the event.willCommit with the SCP even though the SCP is not in the row?

if(event.willCommit){if(event.value == "") this.resetForm (["SCP", "WMs1E", "MSI1", "MSL1", "MSE1", "MSLd1", "MSES1_Hid"]);

else SetWeaponMissileOneFieldValues(event.value);

}