function validate_required(field,alerttxt)
{
with (field)
  	{
  	if (value==null||value=="")
    	{
    	alert(alerttxt);return false;
    	}
  	else
   		{
    	return true;
    	}
  	}
}

function validate_email(field,alerttxt)
{
with (field)
  {
  beforea=value.indexOf("@");
  beforedot=value.lastIndexOf(".");
  if (beforea<1||beforedot-beforea<2)
    {
	alert(alerttxt);
	return false;
	}
  else 
  	{
  	return true;
  	}
  }
}

function limitLength(limitField, limitNum) 
{
    if (limitField.value.length > limitNum) 
	{
        limitField.value = limitField.value.substring(0, limitNum);
    } 
}

function validate_form(thisform)
{
with (thisform)
	{
	if (validate_email(email,"The Email Address you provided is not valid.")==false)
  	{
	email.focus();
	return false;
	}
	
	if (validate_required(title,"Please provide a book title.")==false)
  	{
	title.focus();
	return false;
	}
  
    if (validate_required(description,"Please provide a description of the book.")==false)
    {
	description.focus();
	return false;
	}
  }
}