Regex in JS not working, but working in PHP

I’ve got a preg_match in PHP that is working. It attempts to check a value for non-US keyboard characters:

if( preg_match( '/[^\\x20-\\x3B\\x3D\\x3F-\\x7E\\s]/', $value ) )
{
  // ...
}

So, this is working. If I put foreign chars in $value, it definitely finds a match. JS on the other hand, not working with the same regex:

var regex = /[^\\x20-\\x3B\\x3D\\x3F-\\x7E\\s]/;
if( this.value.search(regex) != '-1' ){
  // ...
}

Since I don’t read or speak any foreign languages, I use charset restriction to keep spam from going through my forms, but I want to detect it client side if possible. Any help is appreciated.

It appears that because of the way I was using preg_match vs replace, I needed my regex in JS to include a g modifier…