Need to validate values of few fields before submission

[S]

We want to validate values of few fields before submitting form. How we can do that.

[Mizan]

There are many ways of doing this , I would suggest using script runner plugin , script validator

[S]

Script runner plugin only works during workflow. My requirement is I want to create customsed script for only validating issues for particular issue type during create and edit issues.

[Mizan]

Ok , so you need to validate fields only if a particular issue type is selected .

You will have to write a javascript which will check the issue type and based on that validate the field on create and edit issue . and paste this script in the field description

You can even have a look at the Behaviours plugin