How To Avoid String Index OutOfBounds Exception

The method I am trying to successfully write is startsWith(String s1, String s2)

The intention of the code is to return true if s2 starts with the string s1, and false otherwise. For example,

x.startsWith("Maplestory","Maple"); Should return true.

This code partially works, depending on the values entered into it. When it is supposed to return true, it does do this. When it is meant to return false, I get a StringIndex OutOfBounds Exception.
 
public class CC02{
String remove1(char c, String s){
String to_return="";
while(true){
if(s.equals(""))
return to_return;

[Code] ....

The method I have written uses one other method from my code, which is "reverse". Any way to return false without getting this error.