function check(formname, submitbutton) 
{
  var errors = '';
  errors += checkText(formname, 'email', 'Email Address');
  errors += checkText(formname, 'mobilenumber', 'Mobile Number');
  errors += checkNum(formname, 'mobilenumber', 'Mobile Number');
  checkThisForm(formname, submitbutton, errors);
}

function postit()
{    
	 //check postcode format is valid
	 test = document.portForm.postcode.value; size = test.length
	 test = test.toUpperCase(); //Change to uppercase
 	 while (test.slice(0,1) == " ") //Strip leading spaces
  	 {
  	 test = test.substr(1,size-1);size = test.length
  	 }
 	 while(test.slice(size-1,size)== " ") //Strip trailing spaces
  	 {
	 test = test.substr(0,size-1);size = test.length
  	 }
 	 document.portForm.postcode.value = test; //write back to form field
 	 if (size < 6 || size > 8){ //Code length rule
  	 alert(test + " is not a valid postcode - wrong length");
  	 document.portForm.postcode.focus();
  return false;
}
 	if (!(isNaN(test.charAt(0))))
	{ //leftmost character must be alpha character rule
   alert(test + " is not a valid postcode - cannot start with a number");
   document.portForm.postcode.focus();
   return false;
  }
 if (isNaN(test.charAt(size-3))){ //first character of inward code must be numeric rule
   alert(test + " is not a valid postcode - alpha character in wrong position");
   document.portForm.postcode.focus();
   return false;
  }
 if (!(isNaN(test.charAt(size-2)))){ //second character of inward code must be alpha rule
   alert(test + " is not a valid postcode - number in wrong position");
   document.portForm.postcode.focus();
   return false;
  }
 if (!(isNaN(test.charAt(size-1)))) 
  { //third character of inward code must be alpha rule
   alert(test + " is not a valid postcode - number in wrong position");
   document.portForm.postcode.focus();
   return false;
  }
 if (!(test.charAt(size-4) == " "))
  {//space in position length-3 rule
   alert(test + " is not a valid postcode - no space or space in wrong position");
   document.portForm.postcode.focus();
   return false;
   }
 count1 = test.indexOf(" ");count2 = test.lastIndexOf(" ");
 if (count1 != count2)
  {//only one space rule
   alert(test + " is not a valid postcode - only one space allowed");
   document.portForm.postcode.focus();
   return false;
  }

return true;
}

function checkThisForm(formname, submitbutton, errors) {
  if (errors == '') {
    eval('document.'+formname+'.'+submitbutton+'.disabled=true');
    eval('document.'+formname+'.submit()');
  } else {
    alert(errors);
  }
}

function checkText(formname, textboxname, displaytext) {
  var localerror = '';
  if(Trim(eval('document.'+formname+'.'+textboxname+'.value'))=='') {
    localerror =  '- '+displaytext+' is Required.\n';
  } else localerror = '';
  return localerror;
}

function checkNum(formname, textboxname, displaytext) {
  var localerror = '';
  if(isNaN(eval('document.'+formname+'.'+textboxname+'.value'))) {
    localerror =  '- '+displaytext+' Should Be A Number With No Spaces.\n';
  } else localerror = '';
  return localerror;
}

function checkSpaces(formname, textboxname, displaytext) {
  var valid = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ_'; // define valid characters
  var localerror = '';
  if(!isValid(Trim(eval('document.'+formname+'.'+textboxname+'.value')), valid)) {
    localerror =  '- '+displaytext+' Should Not Contain Spaces.\n';
  } else localerror = '';
  return localerror;
}

function checkSelect(formname, selectboxname, displaytext) {
  var localerror = '';
  if(eval('document.'+formname+'.'+selectboxname+'.selectedIndex')==0) {
    localerror =  '- '+displaytext+' is Required.\n';
  } else localerror = '';
  return localerror;
}

function getRadio(formname, radioname, displaytext) {
  for (var i=0; i < eval('document.'+formname+'.'+radioname+'.length'); i++) {
    if (eval('document.'+formname+'.'+radioname+'[i].checked')) {
      var rad_val = eval('document.'+formname+'.'+radioname+'[i].value');
      return rad_val;
    }
  }
}

function checkRadio(formname, radioname, displaytext) {
  var localerror = '';
  var rad_val    = '';
  for (var i=0; i < eval('document.'+formname+'.'+radioname+'.length'); i++) { //check every radio button by that name
    if (eval('document.'+formname+'.'+radioname+'[i].checked'))  { //if it is checked
      rad_val += '-';
      }	else rad_val += '';
      }
    if (rad_val=='') {
      localerror =  '- '+displaytext+' is Required.\n';
    }
  return localerror;
}

function autoComplete (field, select, property) {
/*onKeyUp="autoComplete(this,this.form.selectboxname,'value',false)" - add this to textbox where you are typing*/
  var found = false;
  for (var i = 0; i < select.options.length; i++) {
    if (select.options[i][property].toUpperCase().indexOf(field.value.toUpperCase()) == 0) {
      found=true; break;
    }
  }
  if (found) {
    select.selectedIndex = i;
  } else {
    select.selectedIndex = -1;
  }
  if (field.createTextRange) {
    if (!found) {
      field.value=field.value.substring(0,field.value.length-1);
      return;
    }
    var cursorKeys ="8;46;37;38;39;40;33;34;35;36;45;";
    if (cursorKeys.indexOf(event.keyCode+";") == -1) {
      var r1 = field.createTextRange();
      var oldValue = r1.text;
      var newValue = found ? select.options[i][property] : oldValue;
      if (newValue != field.value) {
        field.value = newValue;
        var rNew = field.createTextRange();
        rNew.moveStart('character', oldValue.length) ;
        rNew.select();
      }
    }
  }
}

function Trim(s) {
  while ((s.substring(0,1) == ' ') || (s.substring(0,1) == '\n') || (s.substring(0,1) == '\r')) {
    s = s.substring(1,s.length);
  }
  while ((s.substring(s.length-1,s.length) == ' ') || (s.substring(s.length-1,s.length) == '\n') || (s.substring(s.length-1,s.length) == '\r')) {
    s = s.substring(0,s.length-1);
  }
  return s;
}

function isValid(string,allowed) {
//  var valid = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ'; // define valid characters
    for (var i=0; i< string.length; i++) {
      if (allowed.indexOf(string.charAt(i)) == -1) return false;
    }
    return true;
}