webform html

I have web application written in with masterpage.
and my question is. If I have html submit button, and I want to do the validation. Just check e.g. DOB is in date format and etc.
How can I do that?

 <div class="ui-input">
<input type="date" required tabindex="3" maxlength="10" name="dob" id="dob" onkeydown="return DateFormat(this, event.keyCode)" placeholder="Enter DOB" value="<%= GetDOB(Request.QueryString["Primary DOB"]) %>" class="form-control" />
											<label class="ui-icon"><i class="fa fa-birthday-cake"></i></label>
                                             <p id="exactAge"></p>

Open in new window

 <input type="submit" id="submit" name="submit"   value="Submit Now" class="btn btn-red btn-lg btn-block" />
Who is Participating?

[Product update] Infrastructure Analysis Tool is now available with Business Accounts.Learn More

I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

David Johnson, CD, MVPOwnerCommented:
Why not use a calendar control? that way you will always get a date

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today

From novice to tech pro — start learning today.