s2 = 0;

function fn_on_load() {
	  s1 = document.getElementById('shell_1').clientHeight;
		if (s2==0) s2 = document.getElementById('shell_2').clientHeight;
	  s3 = document.getElementById('shell_3').clientHeight;
    if (self.innerHeight) // all except Explorer
    {
		  y = self.innerHeight;
    }
    else if (document.documentElement && document.documentElement.clientHeight)
    	// Explorer 6 Strict Mode
    {
		  y = document.documentElement.clientHeight;
    }
    else if (document.body) // other Explorers
    {
 	     y = document.body.clientHeight;
    }
	  if ((s1 + s2 + s3) < y) {
	    h = y - (s1 + s3);
	    document.getElementById('shell_2').style.height = h + 'px';
			document.getElementById('c_frame').style.height =  h + 'px';
	  }
}