valid date ให้อยู่ในรูปแบบ (mm/dd/yyyy):
<script type="text/javascript">
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
}
</script>[
ตัวอย่าง Form
<form onSubmit="return checkdate(this.mydate)">
<input type="text" name="mydate" />
<input type="submit" value="submit" /><br />
<b>Valid date format:</b> mm/dd/yyyy
</form>;submit" value="submit">
</form>