 While on study, you will take the study dose either erlotinib hydrochloride or placebo by mouth, in tablet form, once a day. Tablets should be taken in the morning 1 hour before or 2 hours after a meal, other medications, vitamins, and iron supplements, with no more than 7 ounces of water. You should take the study dose around the same time every day. Every attempt should be made to keep from vomiting the dose, for at least 30 minutes after taking it. For example, if you feel nauseated before or after taking the study dose, anti-nausea medications should be used. If you vomit after taking the study dose, the dose can be taken again only if the tablets can actually be seen and counted in other words, they have not dissolved yet. You will need to note the time you take each dose of medication throughout the study on a calendar that the study nurse will give to you. 