var DivNumber = 4;
var DivName = "Buy";
function HideTable(Number)
{
    for(var i=0;i<DivNumber;++i)
    {
        if (i != Number) 
        {
            document.getElementById(DivName+i).style.display="none";
        }
        else
        {
            document.getElementById(DivName+i).style.display="block";
        }   
    }
}