How in the world did you decide on 2048???
ANY character code outside the range 0 to 127 will *NOT* be an ASCII character, which is what I would assume you meant by non-English.
Here, a counter example to your silly choice of 2048:
for ( c = 128; c < 2048; ++c )
document.write( String.fromCharCode(c) );
Do *THOSE* look like "English" characters to you???