My wife needs to transit through a US airport for not more than 5 hours in February 2010 in order to go back to her birth country. However, she filled out by mistake a DS-160 Non-immigrant visa to submit to the US consulate in Vancouver (Canada) because at the US consulate in Vancouver they require DS-160 Forms to be submitted to them. However, she decided to fill out a second form called DS-156 in order to apply to another US consulate in Canada (in Calgary) for the same US transit visa to get an earlier appointment there. What does she has to do now to correct this situation ?
Contact the consulate. If they have not already done so, they will correct the situation upon request.