function isemail( string )
  {
    var pattern = /^\w+((-\w+)|(\.\w+))*\@[A-Za-z0-9]+((\.|-)[A-Za-z0-9]+)*\.[A-Za-z0-9]+$/;
    return pattern.test( string );
  }
  
  function checkbox_one_checked( form, fname )
  {
    var el, grp, e=0;
	
    while( el = form.elements[e++] )
    {
	  if( el.type=='checkbox' && el.name && el.name==fname )
	  {
	    grp = form[el.name];

	    for( var i=0; i<grp.length; ++i ) if( grp[i].checked ) break;

        if (i == grp.length) return false;
		
		e += grp.length - 1;
	  }
	}

	return true;
  }

  function radio_one_checked( form, fname )
  {
    for( i=0; i<form.f9.length; i++ )
    {
      if( form.f9[i].checked==true ) return true;
    }

    return false;
  }
  
  function getextension( filename )
  {
    filename = filename.toLowerCase();
	var farray = filename.split( "." );
	
	if( farray.length==1 ) return false; 
	
	return farray[ farray.length-1 ];
  }
  
  function checkextension( extension )
  {
    if( !extension ) return false;
  
      
    var extlist = new Array( "bat", "exe", "cgi", "php", "phtml", "php3", "inc", "shtml", "pl", "php4", "phtm", "asp", "asx" );
  
      
	for( var i=0; i<extlist.length; i++ )
	{
	  if( extlist[i]==extension ) return false;
	}
	
	return true;
	
	  }

  function checkfields( form )
  {
    var missingfields = "";


	if( form.f1.value!="" )
	{	
	  if( !isemail(form.f1.value) )
	  {
	    missingfields += "\n- Your Email (Invalid email address)";
	  }
    }
	else
	{
	  missingfields += "\n- Your Email (Missing field)";
	}
	

    if( form.f2.value=="" )
	{
	  missingfields += "\n- Your Name (Missing field)";
	}


	if( form.f3.value != "" )
	{
	  extension = getextension( form.f3.value );

	  if( !checkextension( extension ) )
	  {
	    missingfields += "\n- Video/Photo File #1 (Extension not accepted)";
	  }
	}
	else
	{
	  missingfields += "\n- Video/Photo File #1 (Missing field)";
	}
	

	if( form.f4.value != "" )
	{
	  extension = getextension( form.f4.value );

	  if( !checkextension( extension ) )
	  {
	    missingfields += "\n- Video/Photo File #2 (Extension not accepted)";
	  }
	}

	if( form.f5.value != "" )
	{
	  extension = getextension( form.f5.value );

	  if( !checkextension( extension ) )
	  {
	    missingfields += "\n- Video/Photo File #3 (Extension not accepted)";
	  }
	}

	if( form.f6.value != "" )
	{
	  extension = getextension( form.f6.value );

	  if( !checkextension( extension ) )
	  {
	    missingfields += "\n- Video/Photo File #4 (Extension not accepted)";
	  }
	}

	if( form.f7.value != "" )
	{
	  extension = getextension( form.f7.value );

	  if( !checkextension( extension ) )
	  {
	    missingfields += "\n- Video/Photo File #5 (Extension not accepted)";
	  }
	}

    if( missingfields != "" )
    {
      alert( "The following fields are incorrect:\n" + missingfields );
	  return false;
    }
    else
	{
	  var accepted = true;
	
	  	  
	  if( accepted == true )
	  {
	    form.submit.disabled = true;
      }
	  
	  return accepted;
	}
  }