var min=10;
var max=18;
function increaseFontSize() {
   var p = document.getElementsByTagName('p');
   for(i=0;i<p.length;i++) {
      if(p[i].style.fontSize) {
         var s = parseInt(p[i].style.fontSize.replace("px",""));
      } else {
         var s = 12;
      }
      if(s!=max) {
         s += 1;
      }
      p[i].style.fontSize = s+"px"
   }
}
function decreaseFontSize() {
   var p = document.getElementsByTagName('p');
   for(i=0;i<p.length;i++) {
      if(p[i].style.fontSize) {
         var s = parseInt(p[i].style.fontSize.replace("px",""));
      } else {
         var s = 12;
      }
      if(s!=min) {
         s -= 1;
      }
      p[i].style.fontSize = s+"px"
   }   
}


//============================for related audio video==============
function expandingWindow(website) {
var windowprops='width=100,height=100,scrollbars=yes,status=no,resizable=no'
var heightspeed = 2; // vertical scrolling speed (higher = slower)
var widthspeed = 4;  // horizontal scrolling speed (higher = slower)
var leftdist = 300;    // distance to left edge of window
var topdist = 100;   // distance to top edge of window

if (window.resizeTo&&navigator.userAgent.indexOf("Opera")==-1) {
var winwidth = window.screen.availWidth - 550;
var winheight = window.screen.availHeight - 200;
var sizer = window.open("","","left=" + leftdist + ",top=" + topdist +","+ windowprops);
//for (sizeheight = 1; sizeheight < winheight; sizeheight += heightspeed)
//sizer.resizeTo(winwidth, sizeheight);
for (sizewidth = 1; sizewidth < winwidth; sizewidth += widthspeed)
sizer.resizeTo(sizewidth, winheight);
sizer.location = website;
}
else
window.open(website,'mywindow');
}