function alertField(text) {
    document.getElementById('alert').innerHTML = text;
}
function checkPhone(type,area,prefix,suffix) {
    var v = true;
    if(isEmpty(area))
        alertField("Please enter the "+type+" number with area code");
    else if(isNaN(area.value))
        alertField("The "+type+" area code must be a number");
    else if(area.value.length<3)
        alertField("3 digits are required for the "+type+" area code.");
    else if(isEmpty(prefix))
        alertField("Please enter the "+type+" prefix.");
    else if(isNaN(prefix.value))
        alertField("The "+type+" prefix must be a number");
    else if(prefix.value.length<3)
        alertField("3 digits are required for the "+type+" prefix.");
    else if(isEmpty(suffix))
        alertField("Please enter the "+type+" suffix.");
    else if(isNaN(suffix.value))
        alertField("The "+type+" suffix must be a number");
    else if(suffix.value.length<4)
        alertField("4 digits are required for the "+type+" suffix.");
    else
        v = false;
    return(v);
}
function checkZip(prefix,suffix) {
    var v = true;
    if(isEmpty(prefix))
        alertField("Please enter a zip code.");
    else if(isNaN(prefix.value))
        alertField("The zip code must be a number");
    else if(prefix.value.length<5)
        alertField("5 digits are required for a zip code.");
    else if(!isEmpty(suffix) &&
            isNaN(suffix.value))
        alertField("The extended zip code must be a number.");
    else if(!isEmpty(suffix) &&
            suffix.value.length<4)
        alertField("4 digits are required for the extended zip code.");
    else
        v = false;
    return(v);
}
function isEmpty(v) {
    var t = false;
    var s = new String(v.value);
    if(s=="") t = true;
    return(t);
}
function isEmailEmpty(v) {
    var t = isEmpty(v);
    var p = new String(v.value);
    if(!t) {
        if(p.indexOf(".")==-1)
            t = true;
        else if(p.indexOf("@")==-1)
            t = true;
    }
    return(t);
}
function limitText(field,max) {
  var diff = max - field.value.length;
  if (diff < 0) {
    field.value = field.value.substring(0,max);
    diff = max - field.value.length;
  }
}