I have a script that looks like this

#!/bin/bash

function something() {
 echo "hello world!!"
}

something | tee logfile 

I have set the execute permission on this file and when I try running the file like this

 $./script.sh

it runs perfectly fine, but when I run it on the command line like this

$sh script.sh 

It throws up an error. Why does this happen and what are the ways in which I can fix this.