JS:Function
function ValidateFormNew(inputFieldId, outputFieldId)
{
var age;
var input = document.getElementById(inputFieldId).value;
var pyear = parseInt(input.substring(6,10));
var pmonth = parseInt(input.substring(3,5)) - 1;
var pday = parseInt(input.substring(0,2));
today = new Date();
year = today.getFullYear() ;
month = today.getMonth();
day = today.getDate();
if ( month < pmonth )
{
age = year - pyear - 1;
}
else if ( month > pmonth )
{
age = year - pyear;
}
else if ( month == pmonth )
{
if ( day < pday )
{
age = year - pyear - 1;
}
else if ( day > pday )
{
age = year - pyear;
}
else if ( day == pday )
{
age = year - pyear;
}
}
if (age != undefined)
{
document.getElementById(outputFieldId).value = age;
}
ValidateForm(inputFieldId);
}
-------------------------------------------------
Server Side:
TxtMDOB.Attributes.Add("Onfocusout", "ValidateFormNew('" & TxtMDOB.ClientID & "','" & TxtMAge.ClientID & "');")