var but1;
var but2;

function button1()
{ 
  if((event.which || event.keyCode) && (but1 != null)) {
    if ((event.which == 13) || (event.keyCode == 13)) {
      document.getElementById(but1).click();
      return false;
    }
  } 
  else {
    return true;
  }
}

function button2()
{
  if((event.which || event.keyCode) && (but2 != null)) {
    if ((event.which == 13) || (event.keyCode == 13)) {
      document.getElementById(but2).click();
      return false;
    }
  } 
  else {
    return true;
  }
}

for ( var prop in document.forms.__aspnetForm ) {
  if ( prop.indexOf('defaultframework:') > -1 ) {
  //document.write(prop + "<br />");  
    if ( prop.indexOf('Quicksearch') < 0  && but1 == null && (document.getElementById(prop).type == "submit" || document.getElementById(prop).type == "button") )
      but1 = prop;
    if ( prop.indexOf('Quicksearch') > -1 && but2 == null && (document.getElementById(prop).type == "submit" || document.getElementById(prop).type == "button") )
      but2 = prop;
  }
}

for ( var prop in document.forms.__aspnetForm ) {
  if (prop.indexOf('defaultframework:') > -1) {
    if ( prop.indexOf('Quicksearch') < 0  && (document.getElementById(prop).type == "text" || document.getElementById(prop).type == "textarea" ))
      document.getElementById(prop).attachEvent ('onkeydown', button1);
    if ( prop.indexOf('Quicksearch') > -1 && (document.getElementById(prop).type == "text" || document.getElementById(prop).type == "textarea" ))
      document.getElementById(prop).attachEvent ('onkeydown', button2);
  }
}