一个自动适应不同分辨率的弹出类JPopup

/*================================= 弹出类 Popup{===================================*/
function JPopup(urlpath) {
    this.url = urlpath;
    this.defaultwidth = 366;     //the width of the window
    this.defaultheight = 400;    //the height of the window
}

JPopup.prototype.status = 'no';
JPopup.prototype.defaultScreenRate_width = 1024;     //the default width of the screen
JPopup.prototype.defaultScreenRate_height = 768;     //the default height of the screen

JPopup.prototype.parseWidth = function(value) {  
    if(isNaN( parseInt(value) ))
        return  this.defaultwidth + this.defaultScreenRate_width / screen.availWidth -1;
    else
        return value + this.defaultScreenRate_width  / screen.availWidth - 1;
}

JPopup.prototype.parseHeight = function(value) {  
    if(isNaN( parseInt(value) ))
       return  this.defaultheight  + this.defaultScreenRate_height  / screen.Height - 1;
    else
       return  value + this.defaultScreenRate_height  / screen.Height - 1;
}

JPopup.prototype.showDialog = function(width, height) { //window.showModalDialog  
    var width1 = this.parseWidth(width);
    var height1=  this.parseHeight(height);
    showModalDialog( this.url, window, 'center:Yes; dialogWidth:'+ width1.toString() +'px; dialogHeight:'+ height1.toString() +'px; status:no;');
}

JPopup.prototype.show = function(width, height) {  //window.open
    this.show('replace', width, height, 'yes', 'yes', 'no');
}

JPopup.prototype.show = function(width, height, scrollbars, resizable) {  //window.open
    this.show('replace', width, height, scrollbars, resizable, 'no');
}

JPopup.prototype.show = function(target, width, height, scrollbars, resizable, toolbar) {  //window.open
    width = this.parseWidth(width);
    height= this.parseHeight(height);
    var left = this.centerLeft(width);
    var top = this.centerTop(height);
      
    open(this.url, target, 'left='+ left +';top='+ top +';status='+ this.status + '; width='+ width +'; height='+ height +'; scrollbars='+ scrollbars +'; resizable='+ resizable+ '; toolbar='+ toolbar +';');
}

JPopup.prototype.fullScreen = function() {
    open(this.url, 'replace', 'fullscreen=yes; status='+ this.status + '; ');
}

JPopup.prototype.centerLeft = function(width) {
    var screenWidth = screen.availWidth;
    return ((screenWidth - width) / 2);
}

JPopup.prototype.centerTop = function(height) {
    var screenHeight = screen.Height;
    return ((screenHeight - height) / 2);
}
/*================================= }弹出类 Popup===================================*/