var error = false;
var error_message = "";
var form = "";
var txtsize ="";
 
function check_flag(field_name, field_string) {
  if (form.elements[field_name] && (form.elements[field_name].type != "hidden")) {
    var field_value = form.elements[field_name].value;
    if (field_value < 4 || field_value > 12) {
       error_message = error_message + "* " + field_string + " must be an even number between 4 and 12" + "\n";
       error = true;
    } else if ( (field_value % 2) != 0) {
       error_message = error_message + "* " + field_string + " must be an even number between 4 and 12" + "\n";
       error = true;
    }
  }
}

function checknotblank(field_name, field_string) {
  if (form.elements[field_name] && (form.elements[field_name].type != "hidden")) {
    var field_value = form.elements[field_name].value;
    if (field_value == '') {
      error_message = error_message + "* " + field_string + " must not be blank" + "\n";
      error = true;
    }
 }
}

function checknumber(field_name, field_string) {
  if (form.elements[field_name] && (form.elements[field_name].type != "hidden")) {
    var field_value = form.elements[field_name].value;
    if (field_value == '') {
      error_message = error_message + "* " + field_string + " must not be blank" + "\n";
      error = true;
    } else if (isNaN(field_value)) {
      error_message = error_message + "* " + field_string + " must be numeric" + "\n";
      error = true;
    } 
  }
}

function checkmax(field_name, field_string, maxval) {
  if (form.elements[field_name] && (form.elements[field_name].type != "hidden")) {
    var field_value = form.elements[field_name].value;
    if (field_value > maxval) {
      error_message = error_message + "* " + field_string + " must be less than " + maxval + "\n";
      error = true;
    } 
  }
}

function check_cart_nologo(form_name, product) {
  form = form_name;

  error = false;
  error_message = "Errors have occurred during the processing of your form.\n\nPlease make the following corrections:\n\n";

  if (product == 70) {
    checknumber("id[txt_21]", "TxtSize"); 
    if (!error)  
        checkmax("id[txt_21]", "TxtSize", 30); 
    if (!error)  
        checknotblank("id[txt_20]", "MilitaryText"); 
  } else if (product == 71) {
        checknotblank("id[txt_29]", "FuelSystemText"); 
  } else if (product == 73) {
    checknumber("id[txt_23]", "Diameter"); 
    if (!error)  
        checkmax("id[txt_23]", "Diameter", 30); 
  } else if ( (product == 74) || (product == 79) || (product == 80) || (product == 81) || (product == 82) ) {
    checknumber("id[txt_24]", "Length"); 
    if (!error)  
        checkmax("id[txt_24]", "Length", 30); 
  } else if ( (product == 69) || (product == 76) || (product == 77) || (product == 78) ) {
    checknumber("id[txt_18]", "FlagSize"); 
    if (!error) 
       check_flag("id[txt_18]", "FlagSize");  
  }
  if (error == true) {
    alert(error_message);
    return false;
  } else {
    return true;
  }
}


function estimate(price) {
  var size = document.getElementById("attrib-21-0"); 
  if (isNaN(size.value) || (size.value == '') ) {
      alert("Please fill in size with a number"); 
      return; 
  }
  alert(size.value * price);
}