asp.net - Need validation check which prompt as soon as user leave the control -

We are developing an application where we have the form to fill users. Here is the scenario for some areas:

1. Name: Number is not included as 123, but it can be alpha-numeric like mynangal123 but not special character
2. birth Date: mm.dd.yyyy or dd / mm / yyy or yyyy / mm / dd etc. Characters are not included as there are specific formats
3. TAXID can be number but not as numeric as it is " 123 may be "but it can also be T-125 by 123

Now, as per the requirement we need users Must be certified for specific input if it does not enter a specific entry. As the username is entered in 123456, there should be a message box on "Please enter a valid name" to give a warning. Restrictions: We have an option of javascript but most of it is not recommended in the scenario, so we need custom legalization or something that will solve our problem.

Please provide some practical solutions for this issue.

Thanks in advance.

Use it for support for server side & amp; Client side legalization