[JavaScript] Trouble memory __java

When you write JS, you run into a problem:
Comparison of
Document.onmousedown = Testmouse; Executable
And
Document.onmousedown = Testmouse (); (Not executable)

Testmouse is a function.

After looking for the information to understand. In fact Document.onmousedown = Testmouse; Equivalent to Document.onmousedown = function () {testmouse ()};
That is, you can write this:
Document.onmousedown = function () {testmouse ()};

Parenthesized is: Execute function, return execution result
Without parentheses: Return the function itself (which can be considered "pointers")

Refer to here:
http://community.csdn.net/Expert/topic/3667/3667592.xml?temp=.4690363

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To move to open a new window:
var x=0;
function MoveWindow ()
{
x=x+1;
if (win!= null && win.opener!= null)
{
Win.opener = self; Win.moveto (x,100);
Window.settimeout ("MoveWindow ()", 1);
}
}