// JavaScript Document
function checkSubmit() {
	if(document.getElementById("donaform").donate_tree.value=="" && document.getElementById("donaform").donate_bfi.value=="")
	{
		alert("Please enter a donation amount in at least one field before continuing");
		return false;
	}
	if (document.getElementById("donaform").donate_tree.value<10 && document.getElementById("donaform").donate_tree.value!="") {
		alert("We're sorry, the minimum donation amount to plant a tree is $10.  Please enter a number greater than or equal to 10 to continue.");
		return false;		
	}

}

function isNumeric(elem, helperMsg){
	var numericExpression = /^[0-9]+$/;
	if(elem.value.match(numericExpression) || elem.value== ""){
		return true;
	}else{
		alert(helperMsg);
		elem.focus();
		return false;
	}
}