Eliminating letter of a string

1

This code just does what it says.


myString="This code eliminates letter \"o\"."
letterKill =function(letter){
	while(found!=-1){
		found=myString.indexOf(letter)
		if(found!=-1){
			myString=myString.slice(0,found)+myString.slice(found+1)
		}
	}
}
letterKill("o")
trace(myString)

I have two questions:

1)How can I make it eliminate more than one letter.

2)If I want to eliminate all the “t`s” , how do I eliminate the “T” (capital).