Operation wait effect, covering layer JS

Function closeloading ()
{
VaR loaddiv;
VaR bgdiv;
Showallselect ();
Bgdiv = Document. getelementbyid ("bgdiv ");
Loaddiv = Document. getelementbyid ("loaddiv ");
If (bgdiv)
{
Document. Body. removechild (bgdiv );
}
If (loaddiv ){
Document. Body. removechild (loaddiv );
}
Document. Body. style. cursor = "default ";
}
Function showloading (){
Hideallselect ();
VaR loaddiv;
If (loaddiv = Document. getelementbyid ("loaddiv ")){
Loaddiv. style. Display = "Block ";
} Else {
Loaddiv = Document. createelement ("Div ");
Loaddiv. ID = "loaddiv ";
Loaddiv. style. Position = "absolute ";
Loaddiv. style. zindex = 1000;
Loaddiv. style. Display = "Block ";
Loaddiv. style. Left = 0;
Loaddiv. style. Top = 0;
Loaddiv. style. Border = "1px solid gray"
Loaddiv. style. Background = "# ffffff"
Loaddiv. style. Padding = "5 ";
}

VaR scrolltop = 0;
VaR clienthig = 0;
If(top.document.doc umentelement & top.document.doc umentelement. scrolltop ){
Scrolltop = top.document.doc umentelement. scrolltop;
} Else if (document. Body ){
Scrolltop = top.doc ument. Body. scrolltop;
}

Clienthig = Document. Body. clientheight;

VaR scrollwid = Document. Body. scrollwidth/2-150;
Loaddiv. style. Left = scrollwid + "PX ";
Loaddiv. style. Top = (scrolltop + clienthig/2) + "PX ";

Loaddiv. innerhtml = " Document. Body. style. cursor = "wait ";


VaR swidth, sheight;
Swidth = Document. Body. scrollwidth; // The page width in the browser workspace or the screen. Width // The Screen width
Sheight = Document. Body. scrollheight; // screen height (vertical resolution)


// Background layer (the size is the same as the valid area of the window, that is, when the dialog box is displayed, the background is displayed as radial Transparent gray)
VaR bgobj = Document. createelement ("Div"); // create a div object (background layer) // dynamically create an element. The created Div
// Define the DIV property, that is, equivalent to (but not true, the object property must be defined
// <Div id = "bgdiv" style = "position: absolute; top: 0; Background-color: #777; filter: progid: dximagestransform. microsoft. alpha (style = 3, opacity = 25, finishopacity = 75); opacity: 0.6; left: 0; width: 918px; Height: 768px; Z-index: 10000; "> </div>
Bgobj. setattribute ('id', 'bgdiv ');
Bgobj. style. Position = "absolute ";
Bgobj. style. Top = "0 ";
Bgobj. style. Background = "# ffffff ";
Bgobj. style. Filter = "progid: DXImageTransform. Microsoft. Alpha (style = 3, opacity = 25, finishopacity = 75 ";
Bgobj. style. Opacity = "0.6 ";
Bgobj. style. Left = "0 ";
Bgobj. style. width = swidth + "PX ";
Bgobj. style. Height = sheight + "PX ";
Bgobj. style. zindex = "10000 ";
// Bgobj. innerhtml = "<IFRAME src = 'javascript: false' style = 'position: absolute; visibility: Inherit; top: 0px; left: 0px; width: 100px; Height: 200px; z-index:-1; '> </iframe> ";
// Bgobj. innerhtml + = "filter = 'progid: DXImageTransform. Microsoft. Alpha (style = 0, opacity = 0 )'";
// Bgobj. innerhtml + = "> </iframe> ";
Document. Body. appendchild (bgobj); // Add the DIV object to the body.

Document. Body. appendchild (loaddiv );

}

Function hideallselect ()
{
Objs = Document. getelementsbytagname ("select ");
For (I = 0; I <objs. length; I ++)
{
Objs [I]. style. Display = "NONE ";
}
}

Function showallselect ()
{
Objs = Document. getelementsbytagname ("select ");
For (I = 0; I <objs. length; I ++)
{
Objs [I]. style. Display = "";
}
}