Function error using Input Command

I am making a function for a class project and I am having trouble finding and fixing the error. When I try to run this function it asks me to input the type of metal I am using but after I type in Al1 for example, it keeps asking me to input the type of metal again. If I type in something other than Al1, nothing happens and it asks for the metal again. How do I fix this?

The function looks like this:

 function [k]=ThCond(T)

 m=input('What metal are you using?','s');
 if m=='Al1'
   if (298<=T)&&(T<=840)
     k=149.7+0.0809*T-(1*10^-4)*T^2;

   end
  else fprintf('Please enter a valid temperature.\n');
 end

 end

Answer 1

[Walter Roberson]

You should be using strcmp() instead of == to compare character vectors.

That code itself would not prompt a second time for input, but it could be that you are calling the code inside a loop.