Engineers !

An Engineer was unemployed for long time. He could not find a job so he opened a medical clinic and puts a sign up outside:
“Get your treatment for $500, if not healed get back $1,000.”

One Doctor thinks this is a good opportunity to earn $1,000 and goes to his clinic.
Doctor: “I have lost taste in my mouth.”
Engineer: “Nurse, please bring medicine from box 22 and put 3 drops in the patient’s mouth.”
Doctor: “This is gasoline!”
Engineer: “Congratulations! You’ve got your taste back. That will be $500.”

The Doctor gets annoyed and goes back after a couple of days later to recover his money.
Doctor: “I have lost my memory, I cannot remember anything.”
Engineer: “Nurse, please bring medicine from box 22 and put 3 drops in the patient’s mouth.”
Doctor: “But that is gasoline!”
Engineer: “Congratulations! You’ve got your memory back. That will be $500.”
The Doctor leaves angrily and comes back after several more days.

Doctor: “My eyesight has become weak.”
Engineer: “Well, I don’t have any medicine for this. Take this $1,000.”
Doctor: “But this is $500 …”
Engineer: “Congratulations! You got your vision back!
That will be $500.”