function validate_required(field,alerttxt)
{
with (field)
{
var length = field.value.length;
if (length<2)
  {return false}
}
}

function validate_form(thisform)
{
var isOK="yes";
with (thisform)
{
	if (validate_required(event_name)==false)
	  {isOK="no"}else {return true};
	if (thisform.city) {
		if (validate_required(city)==false)
			{isOK="no"}else {return true};
	}
	if (thisform.venue) {
		if (validate_required(venue)==false)
			{isOK="no"}else {return true};
	}	
}
if (isOK=="no"){alert("Search Parameters must be at least two characters");return false};
}