Check DateTime format using JS

The below function checks date in mm-dd-yyyy format.


<asp:TextBox ID="txtYearValue" runat="server" onBlur="checkdate(this)"></asp:TextBox>

function checkdate(input)
{
var validformat=/^\d{2}\-\d{2}\-\d{4}$/ //Basic check for format validity
var returnval=false
if (!validformat.test(input.value))
alert("Invalid Date Format. Please correct and submit again.")
else{ //Detailed check for valid date ranges
var monthfield=input.value.split("-")[0]
var dayfield=input.value.split("-")[1]
var yearfield=input.value.split("-")[2]
var dayobj = new Date(yearfield, monthfield-1, dayfield)
if ((dayobj.getMonth()+1!=monthfield)||(dayobj.getDate()!=dayfield)||(dayobj.getFullYear()!=yearfield))
alert("Invalid Day, Month, or Year range detected. Please correct and submit again.")
else
returnval=true
}
if (returnval==false)
      input.select()
return returnval
}