function isBlank(s) 
	{

		for(var i=0;i<s.length;i++){
			var c=s.charAt(i);	
			if((c!=' ') && (c !='\n') && (c!='\t')) return false;
		}
	}

	function checkMailAddress(m)
	{
		if(m.indexOf("@")<1 || m.indexOf(".")<1){
			return false;
		}else{
			if(m.indexOf(".",m.indexOf("@")) > m.indexOf("@") ){
				return true;
			}
			else{
				return false;
			}
		}
	}
	
function valDrop(val) 
{
	if (val == '') return false;
	else return true;
}

	function verify(f)
	{
		var msg;
		var empty_fields="";
		var errors="";

// check if there are any fields that are not optional that are blank 

		for(var i=0;i<f.length;i++){
			var e=f.elements[i];
			var display_name="";

			if(e.name=="to"){ 
				display_name="Destination Email Address";
			}else if(e.name=="from"){
				display_name="Email address";
			}else if(e.name=="subject"){
				display_name="Subject";
			}else if(e.name=="comment"){
				display_name="Comments";
			}else if(e.name=="name"){
				display_name="Name";
			}else if(e.name=="organisation"){
				display_name="Institution";
			}else if(e.name=="country"){
				display_name="Country";
			}else if(e.name=="product"){
				display_name="Product";
			}else if(e.name=="productnew"){
				display_name="Product radio";
			}else if(e.name=="address"){
				display_name="Institution Address";
			}else if(e.name=="question"){
				display_name="Enquiry";
			}else if(e.name=="renewal"){
				display_name="Renewal Number";
			}else if(e.name=="price"){
				display_name="Price";
			}else if(e.name=="position"){
				display_name="Position";
			}

			if(((e.name=="comment") || (e.name=="subject")) && (e.value.length>200)){
				errors+="The "+display_name+" field is too long. Please limit your comments to 200 characters.";
			}
			
			if (e.name=="organisational role"){
				if(valDrop(e.value)==false){
						empty_fields+="\n             "+display_name;
					}
				}

			if(e.name=="from" && !e.optional){
				if(checkMailAddress(e.value)==false){
					errors+="You have supplied an invalid destination email address.";
				}				
			}

			if(e.name=="to" && !e.optional){

				if(checkMailAddress(e.value)==false){
					errors+="You have supplied an invalid destination email address.";
				}
			}

			if(((e.type=="text") || (e.type=="textarea")) && !e.optional){

				if((e.value==null) || (e.value=="") || isBlank(e.value)){
					empty_fields+="\n             "+display_name;
					continue;
				}
			}
			if((e.name=="country")  && !e.optional){

				if((e.value==null) || (e.value=="") || isBlank(e.value)){
					empty_fields+="\n             "+display_name;
					continue;
				}
			}
			if((e.name=="question")  && !e.optional){

				if((e.value==null) || (e.value=="") || isBlank(e.value)){
					empty_fields+="\n             "+display_name;
					continue;
				}
			}
			if((e.name=="productnew")  && !e.optional){

				if((e.value==null) || (e.value=="") || isBlank(e.value)){
					empty_fields+="\n             "+display_name;
					continue;
				}
			}
			if((e.name=="product")  && !e.optional){

				if((e.value==null) || (e.value=="") || isBlank(e.value)){
					empty_fields+="\n             "+display_name;
					continue;
				}
			}
			
		}
		
		

		if(!empty_fields && !errors) return true;

		msg="THIS EMAIL COULD NOT BE SENT\n";

		if(empty_fields){
			msg+="\nThe following required field(s) are empty: "
				+empty_fields+"\n";
		}

		if(errors){
			msg+="\n"+errors;

		}

		alert(msg);
		return false; 

	}