// JavaScript Document

//function to check empty fields

function isEmpty() {

strfield1 = document.forms[0].keyword.value 

    if (strfield1 == "" || strfield1 == null || !isNaN(strfield1) || strfield1.charAt(0) == ' ')
    {
    alert("Inserisci una parola da cercare!")
    return false;
    }

    return true;
}

//function that performs all functions, defined in the onsubmit event handler

function check(){
if (isEmpty()){
		  return true;
}
	return false;
}