Passing parameters to javascript files

params.js

var scripts = document.getElementsByTagName('script'); 
var myScript = scripts[ scripts.length - 1 ]; 
var queryString = myScript.src.replace(/^[^\?]+\??/,''); 
var params = parseQuery( queryString ); 

function parseQuery ( query ) { 
  var Params = new Object (); 
  
  if ( ! query ) return Params; 
  // return empty object 
  var Pairs = query.split(/[;&]/); 
  
  for ( var i = 0; i < Pairs.length; i++ ) { 
    var KeyVal = Pairs[i].split('='); 
    
    if ( ! KeyVal || KeyVal.length != 2 ) continue; 
    
    var key = unescape( KeyVal[0] ); 
    var val = unescape( KeyVal[1] ); 
    
    val = val.replace(/\+/g, ' '); 
    Params[key] = val; 
  } 
  return Params; 
}