function swapon1()
  {
   document.img1.src="img/navigr1.gif";
  }
 function swapoff1()
  {
   document.img1.src="img/navig1.gif";
  }
 function swapon2()
  {
   document.img2.src="img/navigr2.gif";
  }
 function swapoff2()
  {
   document.img2.src="img/navig2.gif";
  }
 function swapon3()
  {
   document.img3.src="img/navigr3.gif";
  }
 function swapoff3()
  {
   document.img3.src="img/navig3.gif";
  }
 function swapon4()
  {
   document.img4.src="img/navigr4.gif";
  }
 function swapoff4()
  {
   document.img4.src="img/navig4.gif";
  }
 function swapon5()
  {
   document.img5.src="img/navigr5.gif";
  }
 function swapoff5()
  {
   document.img5.src="img/navig5.gif";
  }
 function swapon6()
  {
   document.img6.src="img/navigr6.gif";
  }
 function swapoff6()
  {
   document.img6.src="img/navig6.gif";
  }
 function swapon7()
  {
   document.img7.src="img/navigr7.gif";
  }
 function swapoff7()
  {
   document.img7.src="img/navig7.gif";
  }