Unable to read/print value of 'instance.vars.hoursDiffValue1' in Alert activity from previous Javascript activity

JAVASCRIPT ACTIVITY CODE:

var res = sqlSelect(
  "row,diff1:long",
  "SELECT HoursDiff(GetDate(), MAX(tsLog)) AS diff1 FROM NmsTrackingLogRcp"
);

var hoursDiff1 = 0;
if (res.row && res.row.length() > 0) {
  hoursDiff1 = Number(res.row[0].diff1.toString());
}

// Store in the workflow instance variable (available within this workflow run)
instance.vars.hoursDiffValue1 = hoursDiff1;

//logging the hoursDiffValue1
logInfo("hoursDiffValue1: " + instance.vars.hoursDiffValue1);

//Adding if condition

if(instance.vars.hoursDiffValue1 >=1)
{
instance.vars.noTrackingLogCountValue = Number(getOption("avNoTrackingLogCount"));

instance.vars.noTrackingLogCount2= instance.vars.hoursDiffValue1 + instance.vars.noTrackingLogCountValue;
// logging instance.vars.noTrackingLogCount2
logInfo("instance.vars.noTrackingLogCount2: " + instance.vars.noTrackingLogCount2);
// setting Option
setOption("avNoTrackingLogCount" , instance.vars.noTrackingLogCount2);
}

ALERT ACTIVITY CODE:

Hi Team,

<% if (instance.vars.sendtrackingmailpart1 == 1) { %>

<% } %>

<% if (instance.vars.sendbroadlogmailpart1 == 1) { %>

<% } %>

<% if (instance.vars.sendtrackingmailpart2 == 1) { %>

<% } %>

<% if (instance.vars.sendbroadlogmailpart2 == 1) { %>

<% } %>