var currentDate = new Date();
var dateOfContact =
crmForm.all.new_submissiondate.DataValue;
if(dateOfContact != null)
{
var pastMaxDate =
new Date();
currentDate.setHours(0);
currentDate.setMinutes(0);
currentDate.setSeconds(0);
currentDate.setMilliseconds(0);
pastMaxDate.setDate(currentDate.getDate()-14);
pastMaxDate.setHours(0);
pastMaxDate.setMinutes(0);
pastMaxDate.setSeconds(0);
pastMaxDate.setMilliseconds(0);
//Checking
condition for last 15 days
if( !((dateOfContact
<= currentDate) && (dateOfContact >= pastMaxDate)) )
{
crmForm.all.new_submissiondate.DataValue = null;
alert("Valid date range is from "+
pastMaxDate.toLocaleDateString() + " to till today.");
}
}