Avoid auto device capitalization for textfields on mobile

Is there a way to avoid having the device auto-capitalize the first letter for Unity GUI textfields on mobile?

var lastStringLen = stringToEdit.Length;
stringToEdit = GUI.TextField (Rect (10, 10, 200, 20), stringToEdit, 25);
if (lastStringLen == 0 && stringToEdit.Length == 1)
stringToEdit = stringToEdit.ToLower();