Javascript 之“提醒语句”

<input id="phone" name="phone" type="text" size="12"
   onblur="validationNonEmpty(this, document.getElementById('phone_help'))" />
<span id="phone_help" class="help"></span>

function validationNonEmpty(inputField, helpText){
 if(inputField.value.length == 0 ){
   if(helpText != null)
      helpText.innerHTML = "Please enter a value"; return false;
}
 else{
    if (helpText != null)
      helpText.innerHTML = ""; return true;
}
}

这样比alert 的pop-up window 友好很多