I need Custom calculation script for an alert message when a user enters a date prior to the current date but still displays what the user had entered

Adding comments to your code would help you and others understand what your code does.

var sStart = this.getField("EffectiveDate").value; // getf effective date field value;

var d2 = new Date(); // get system date object;

d2.setHours(0,0,0,0); // set system dte object to midnight;

if(sStart.length )

{

// must have a non-empty start date;

var dateStart = util.scand("mm/dd/yyyy",sStart); // convert start date to Date object;

dateStart.setHours(0, 0, 0, 0); // set effective date time to midnight;

if(dateStart.getTime() < d2.getTime() )

{

// error if dateStart value less than sytem date value;

app.alert("The Effective Date entered is before today's date.\nEffective date must be or after " + util.printd("mm/dd/yyyy", d2), 1, 0, "Effective Date Error");

event.value == ""; // clear the entry value;

event.rc = false; // set event return code to false, error;

}

}

You're comparing a string to a date object in this line:

if(sStart < d2 )