Initially i connect to phonegap's database but when i move to the second html page i can;t connect

I am using phonegap's database API in my html/css/js code and i have a problem.Although in the index page i manage to create tables,insert data,select and display them,when i proceed to my second html file i can't access anything from the database.I get SQL error 0.Here is my javascript file for the second html page.Any ideas?

var db;
function ondevre (){
alert('a1');
 $.ajaxSetup({
    crossDomain: true,
    xhrFields: {
        withCredentials: true
    }
});
$.support.cors = true; 
$.mobile.allowCrossDomainPages = true;
 signsql();         
function signsql(){ 
                db = window.openDatabase("Database", "1.0", "Cordova Demo", 2*1024*1024);
                db.transaction(selectDB, errorCB, successCB);     
              function errorCB(err) {
                alert("Error processing SQL: "+err.code);
            }     
            function successCB() {
               alert("YEAH!!!!");
               }    
            function selectDB (tx) {
myname=escape(window.localStorage["myname"]);
var stre='SELECT User_Mail FROM table1 WHERE User_Name="'+myname+'"';
tx.executeSql(stre, [], mnme, function er(e) {alert("error "+e)});
function mnme (tx,result) {
 if (result != null && result.rows != null) {
 alert(result.rows.length);
   for (var i = 0; i < result.rows.length; i++) {
 var row = result.rows.item(i);
 };
 us_mail=row.User_Mail;
      }

}               
            }
    };  

}
$("#ii").ready (function () {

         $("#whole").fadeIn(2500);   
ondevre();
});
app.initialize();