How to create Sessions in phonegap Android apps

How to create Sessions in phonegap Android apps

I am creating an app in which I need a session to store the userId which i
can use later for fetching data from the datadase. I am new to phonegap
Android apps and dont have any knowledge about sessions.So can any one
give me some example or link from where I can understand how to create
session and use it. Thanks in advance. here is the js code:
ftable=results.rows.item(i).from_table;//from database i am getting to
know from which table to call for the select data option in dropdown list
if(ftable.indexOf('#')=='-1'){
from_Table=ftable;
}else{
//**in the from_table there is query which will need session data **//
// from_Table="(select i.industry_id, i.industry_name, i.deleted,
i.comp_code from user_industry_asso cuia, industry i where i.industry_id =
cuia.industry_id and cuia.user_id = '1' order by i.industry_name)";
from_Table="";
split_table=ftable.split('#');
alert("Length: "+split_table.length);
for(var k=0;k<split_table.length;k++){
alert("After split: "+split_table[k]);
if(k%2==1){
from_Table +=eval(split_table[k]);
alert("For loop if condition: "+from_Table);
}else{
from_Table +=split_table[k];
console.log("Else condition: "+from_Table);
}
}
}
var select_optionData1="select "+optionName+"," +optionValue+" from
"+from_Table+" alias where deleted='0' and comp_code='1' order by
"+optionName;
tx.executeSql(select_optionData1,[]);//will get the data from the table
and store in array object which will be called later to create a
dropdownlist
here is the session which i create in the html file:
var userid='1';
window.sessionStorage.setItem('ls_userid',userid);
var userId = window.sessionStorage.getItem('ls_userid');