function getElementsByClassName(clsName) 
{ 
	var arr = new Array(); 
	var elems = document.getElementsByTagName("*");
	for ( var cls, i = 0; ( elem = elems[i] ); i++ )
	{
		if ( elem.className == clsName )
		{
			arr[arr.length] = elem;
		}
	}
	return arr;
}

function addNewTankType(oform) {
	oform["tankNumber"].value++;
	var oNewDiv = document.createElement("DIV");
	document.getElementById('tanks').appendChild(oNewDiv);
	oNewDiv.className="tank_div";
	oNewDiv.innerHTML=document.getElementById('tank_1').innerHTML;
	oNewDiv.id="tank_" + oform["tankNumber"].value;
}

function IsNumeric(field) {
	var ValidChars = "0123456789.";
	var IsNumber=true;
	var Char;
	for (i = 0; i < field.value.length && IsNumber == true; i++) { 
		Char = field.value.charAt(i); 
		if (ValidChars.indexOf(Char) == -1) {
			IsNumber=false;
			field.value='';
			return false;
		};
	};
	return true;
}

function IsEmpty(aTextField) {
   if ((aTextField.value.length==0) ||
   (aTextField.value=='')) {
      return true;
   }
   else { return false; }
}	

function isValidEmail(field) {
	var str=field.value;
	var filter=/^([\w-]+(?:\.[\w-]+)*)@((?:[\w-]+\.)*\w[\w-]{0,66})\.([a-z]{2,6}(?:\.[a-z]{2})?)$/i

	if (filter.test(str)) {
		return true;
	} else {
			field.value='';
			return false;
	};
}

function ValidateForm(form, warningText) {
	var nonEmptyInput = getElementsByClassName('required');
	for(i=0; i<nonEmptyInput.length; i++) {
		if(IsEmpty(nonEmptyInput[i])) { 
			nonEmptyInput[i].focus();
			nonEmptyInput[i].style.backgroundColor='red';
			nonEmptyInput[i].style.color='white';
			alert(warningText);
			return false; 
		} else {
			nonEmptyInput[i].style.backgroundColor='#cccccc';
			nonEmptyInput[i].style.color='black';
		};
	}
	if (form['emailAddress'].value != form['confirmEmailAddress'].value) {
		form['confirmEmailAddress'].value='';
		form['confirmEmailAddress'].style.backgroundColor='red';
		form['confirmEmailAddress'].style.color='white';
		alert('Not a valid e-mail confirmation!');
		return false;
	} else {
		form['confirmEmailAddress'].style.backgroundColor='#cccccc';
		form['confirmEmailAddress'].style.color='black';
	}
		return true;
}