Question about this code

Hi, I'm new to javascript and have been practicing. I'm having trouble with this piece of code. If the prompt has the correct string "luke" inputted I'm expecting it to display the correct alert however I'm getting the else statement instead and I'm unsure as to why?

Hi, I'm new to javascript and have been practicing. I'm having trouble with this piece of code. If the prompt has the correct string "luke" inputted I'm expecting it to display the correct alert however I'm getting the else statement instead and I'm unsure as to why?