var fields = new Array ( 'f_name', 'f_email', 'f_subject', 'f_message' );

function setFocus () {
  this.style.border = "1px solid gray";
}

function clearFocus () {
  this.style.border = "1px solid silver";
}
  
function onLoad () {
  for ( var i = 0; i < fields.length; i++ ) {
    document.getElementById(fields[i]).onfocus = setFocus;	
    document.getElementById(fields[i]).onblur = clearFocus;	
  } 

  document.getElementById('f_name').focus();
}

document.onload = onLoad;