Window Creation In Python

[pythonboy]

if window(myWin,exists=True):
deleteUI (myWin)
myWin = window(title = 'myWindows', mb=1,tlb=1)
showWindow(myWin)

this in short some of my code the problem is when i restart maya each time i have to manually execute this part seperately from the rest

myWin = window(title = 'myWindows', mb=1,tlb=1)

Because python in the start does not know what myWin is

So i tried to define myWin before all this like this :

myWin = '' // empty string right,just variable declaration and definition 0

but then when i write some code in my script and reexecute all the code and the window shows up but the old one stays,and if i keep doing this i will end up with 101 dalmatins hahahaha

You have solution for this guys? regards

[sin3d]

import maya.cmds as cmds
if cmds.window('myWin',exists=True):

cmds.deleteUI('myWin', window=True)

cmds.window('myWin',title = 'myWindows', mb=1,tlb=1)
cmds.columnLayout( adjustableColumn=True )
cmds.button( label='Do Nothing' )
cmds.button( label='Close', command=('cmds.deleteUI("myWin", window=True)') )
cmds.setParent( '..' )
cmds.showWindow('myWin')

[visualfx]

myWin = 'myUniqueWindowName'
if window(myWin,exists=True): deleteUI (myWin)
myWin = window(myWin,title = 'myWindows', mb=1,tlb=1)
showWindow(myWin)