JFrame with four sliders
Naming:
Your class is named Input_Window which violates standard Java naming conventions of PascalCase (without underscores).
Formatting:
An equal sign should be surrounded by spaces:

myslideA = slider(0,10,3,1,true,true);
//and so on...

Visibilities: 


Your JSliders should most probably be private. nobody aside from
your InputWindow should have to know about them. If there's someone out there who wants to know about GUI except the GUI you're doing things wrong ...
slider should also be private. If somebody else uses it, extract it to a utility-class. Hide the information where ever you can. If you don't things may happen with your stuff when you're not watching.

Responsibilities:
Your constructor shouldn't request focus and set the window to visible himself. That's things that should be done in calling code. You don't expect a JFrame to show up on instantiation either, right?