Codezwiz >> Forums >> Javascript Help >> help building a regular expression to validate a date field

I need help creating a regular expression to validate a date field in a form.
The actuall call to validate the form is working fine, I just can not seem to get the regular expression correct. I know JACK about RegExp's.

valid date form: YYYY-MM-DD
example: 2004-09-29

Here is what I have

if(document.form1.issue_date.value=="")
{
alert("Please indicate valid Issue Date!")
document.form1.issue_date.focus()
return false
}
else
{
var reg = /\d(4)-\d(2)-\d(2)/

if(reg.test(document.form1.issue_date.value))
{
alert("This IS a valid date!")
return true
}
else
{
alert("This IS NOT a valid date!")
document.form1.issue_date.focus()
return false
}
}

Hi Mearnheart

How about ...

var objRegExp = /^\d{4}(\-)\d{1,2}\1\d{1,2}/

Breaking it down...

/ : the opening and closing tag to string

^\d{4} : that the string begin with four digits

(\-) : that following the four digits there is an "-"

\d{1,2} : the next portion of string will be one to two digits

\1 : that there is another occurance of the string value to the left that is in parenthesized

\d{1,2} : the next portion of string will be one to two digits

/ : the opening and closing tag to string

As for the script its self how about...

var IssuDate = document.form1.issue_date
var objRegExp = /^\d{4}(\-)\d{1,2}\1\d{1,2}/

if(!objRegExp.test(IssuDate.value)) {
alert("Please indicate valid Issue Date!")
IssuDate.focus()
return false
}else{
alert("This IS a valid date!")
return true
}

thank you very much, worked wonderfully....

mike