// Global variables (capitalized to denote global declaration, usually)
	 var USER = {};    // JSON object will store all user inputs
       var DATA = {};    // JSON object will store the actual data
       var MAP  = {};    // JSON object will store Google Map handles
       var DIND = 0;     // "Data Index" - identifies instance of the data; initialize to zero
	 var nbins = 6;	// number of bins for map colors

       // Initialize USER and MAP objects
       USER[DIND] = {	program: null,
				test_material: null,
				matrix: null, 
				year1: null, 
				year2: null, 
				species: null,
				speciestype: null,
				tissuetype: null,
				analyte: null  };
       MAP[DIND]  = {   map: null };

 
	// function to resent the USER variables           
	function resetUSER() {
			 nbins = 6;	// need to reset this in case it was changed...
		       USER[DIND] = {   program: null,
                        test_material: null,
                        matrix: null,
                        year1: null,
                        year2: null,
                        species: null,
                        speciestype: null,
				tissuetype: null,
                        parametertype: null,
                        analyte: null  };
	}