How to keep website pages have same space& width size when in different browser(design in photoshop)?

First I'm not sure is my question right or not, I'm sorry about my English, if something you don't understand, please ask me directly.

Here is the thing, I'm a newbie in website design field, I have a project recently, as a designer I design pages in photoshop.

And I have already sent some pages to develop to code, and today I found the site page width not the same as the original design, I use my browser to see the width space between the browser edge and logo is little wide than original look, and my client see in her browser, the space is more wider than mine!!

I know I used a fix width based, and I have asked the developer if can changed into Fluid layout, things like use % based, so I think it's more easy to keep a consistent space size and look. And he said :" each lay out will have a main width, and its not support %, when u will use element under the main div then u can use %, but the main div u need to create by pixel, ie. 1024 / 1444." Frankly I'm not very understand what's this mean tho, but see the attached images, so my problems are:

1. if there has a way that I can achive the best effect in most browsers, should I provide you the each main size based on the original version for various screen sizes and devices? I want no matter in what kinds of browser, the space between each element is still as the same as the original style. see the images below, the two screenshots in different broswers are totally different right?! So how should I do to make them have a same space style like the original design(the 2 second one.)? enter image description here |

enter image description here |

the Second one is the original design.

Thanks so much, hopefully I have already explained clearly. Thanks in advance.