Can I get some value from user? (illustrator cs3 script)

I am Designer. But I have to write program.

I will making plugin about draw rectangle.

1. User run illustrator cs3.

2. User click File-Scripts-myDraw

3. Show dialog box. Dialog box have two inputField. User input values.(ex>53.32,   41.2)

4. click 'summit' button.

5. illustrator cs3 draw 53.32 * 41.2 size rectangle!!

I don't know How I made dialogbox...

Is it possible get value from user?

what is 'cin' code as illustrator javascript?  (cin : C++ style input code.)

please help me.