Possible Duplicates:
Best Programming Language for Web Development
How can I choose a web development language?
What language will you choose if you are going to build something big?
What is the right option of programming languages and tools for building our website?
What is the easiest web programing language at....?

Well, I'm more of a basic web designer. I know the easy stuff pretty well. (Ya know, html, css) But I've been trying to take it to the next step and I'm contemplating about what I should learn that will help me out the most in my future web design/programming career, should it be JavaScript or maybe I should try to learn a back end programming language such as PHP.

Lately, I have been hearing about a lot how JavaScript is so great and useful now, because of libraries such as jQuery and what possibility's it can bring by using Node.js and other frameworks. I've only learned the most basic of JavaScript and used some jQuery (mostly plugins) so i wouldn't know at all of what it can actually do.

Would JS being so popular as it is now and useful, be a reason to stick with JavaScript and only learn it that for now?

Or as a web designer, how important would it be to learn how to make a web application/website operate and functional, and know how to work with servers, etc? (Such as getting forms to work and sending data to the server and back) I've took a look at frameworks such as Code Igniter before, and looks really simple to get started with if I try to learn PHP, But I'm not sure how important it is for my career and what I would gain out of it.

I'm asking because I can't decide what I should learn first. When I select it, I really want to take my time and learn the language. I don't want to spend time on learning multiple languages at the same time, so I need to pick wisely. I'm trying to turn the right direction so my career can hopefully be successful in the feature. (If money/gaining a job asked if its important, then its a yeah, it is a bit)

I'm hoping I can get opinions and suggestions on this question, thanks for giving me your thoughts also.