public static void Vertical_Scroll(double verticalPositionY,double verticalUptoScrollY ) throws Exception
{
Dimension dim=driver.manage().window().getSize();
int height =dim.getHeight();
int width= dim.getWidth();
int starty=(int) (height * verticalPositionY);
int x = (int) (width *.50);
int endy =(int) (height * verticalUptoScrollY);
TouchAction t=new TouchAction(funcation.driver);
t.longPress(x, starty).moveTo(x,endy).release().perform();
}