// JavaScript Document

//<SCRIPT LANGUAGE="JavaScript1.1">
// A utility function that returns true if a string contains only 
// whitespace characters.
function isblank(s)
{
    for(var i = 0; i < s.length; i++) {
        var c = s.charAt(i);
        if ((c != ' ') && (c != '\n') && (c != '\t')) return false;
    }
    return true;
}

// This is the function that performs form verification. It will be invoked
// from the onSubmit() event handler. The handler should return whatever
// value this function returns.
function verify(f)

{
    var msg;
    var empty_fields = "";
    var errors = "";

    // Loop through the elements of the form, looking for all 
    // text and textarea elements that don't have an "optional" property
    // defined. Then, check for fields that are empty and make a list of them.
    // Also, if any of these elements have a "min" or a "max" property defined,
    // then verify that they are numbers and that they are in the right range.
    // Put together error messages for fields that are wrong.
    for(var i = 0; i < f.length; i++) {
        var e = f.elements[i];
        if (((e.type == "text") || (e.type == "textarea")  || (e.type == "password") ) && !e.optional) {
            // first check if the field is empty
            if ((e.value == null) || (e.value == "") || isblank(e.value)) {
                empty_fields += "\n          " + e.description;
                continue;
            }

            // Now check for fields that are supposed to be numeric.
            if (e.numeric || (e.min != null) || (e.max != null)) { 
                var v = parseFloat(e.value);
                if (isNaN(v) || 
                    ((e.min != null) && (v < e.min)) || 
                    ((e.max != null) && (v > e.max))) {
                    errors += "- The field " + e.description + " must be a number";
                    if (e.min != null) 
                        errors += " that is greater than " + e.min;
                    if (e.max != null && e.min != null) 
                        errors += " and less than " + e.max;
                    else if (e.max != null)
                        errors += " that is less than " + e.max;
                    errors += ".\n";
                }
            }
			
			
			 // Now check for fields that are supposed 
        // to be emails.
        // Not exactly as described in RFC 2822, but 
        // a rough attempt
        // of the form "local-bit@domain-bit"
        if (e.email && !isblank(e.value))
        {
           var seenAt = false;
           var append = "";
           for(var j = 0; j < e.value.length; j++)
           {
              var c = e.value.charAt(j);
              if ((c == ' ') ||
                  (c == '\n') ||
                  (c == '\t'))
                 append += 
     "\n           - not contain white-space";
              if ((c == '@') && (seenAt == true))
                 append += 
     "\n           - contain only one @";
              if ((c == '@'))
                 seenAt = true;
           }

           if (seenAt == false)
              append += 
     "\n           - contain exactly one @";
           if (append)
              errors += "- The field " +
                        e.description +
                        " must: " + append;
						 errors += ".\n";
        }

			
			
        // Now check for fields that are supposed 
        // to be date.
        if (e.dateFormat && !isblank(e.value))
        {
           var slashCount = 0;
           var append = "";
           var addedError1 = false;
           var addedError2 = false;

           for(var j = 0; j < e.value.length; j++)
           {
              var c = e.value.charAt(j);

              if ((c == '/'))
                 slashCount++;

              if (c != '/' &&
                 (c < '0' || c > '9') &&
                 addedError1 == false)
              {
                 addedError1 = true;
                 append += 
     "\n           - must contain only numbers " +
     "and forward-slashes";
              }
           }

           if (j != 8 || slashCount != 2)
              append += 
     "\n           - must have the format DD/MM/YY";
           if (slashCount != 2)
              append += 
     "\n           - must contain two slashes";
           if (append)
              errors +=  "- The field " + 
                         e.description + 
                         " must: " + append;
        }

        // Now check for fields that are supposed 
        // not to have spaces
        if (e.nospaces)
        {
           var seenAt = false;
           var append = "";

           for(var j = 0; j < e.value.length; j++)
           {
              var c = e.value.charAt(j);

              if ((c == ' ') ||
                  (c == '\n') ||
                  (c == '\t'))
                 errors += "- The field " + e.description +
                           " must not contains white-space";
           }
        }

			
			
        }
    }

    // Now, if there were any errors, display the messages, and
    // return false to prevent the form from being submitted. 
    // Otherwise return true.
	
    if (!empty_fields && !errors) return true;

    msg  = "_________________________________________________________________________\n\n"
    msg += "The form was not submitted because of the following error(s).\n";
    msg += "Please correct these error(s) and re-submit.\n";
    msg += "__________________________________________________________________________\n\n"

    if (empty_fields) {
        msg += "- The following required field(s) are empty:" 
                + empty_fields + "\n";
        if (errors) msg += "\n";
    }
    msg += errors;
    alert(msg);
    return false;
}