function ValidEntry( val ) 
{
var i;
var oneChar;

if( ( val== "" ) || (  val == null ) )
	{
	return false
	}
for( i = 0; i < val.length; i++ ) 
	{
	oneChar = val.substring( i, i + 1 )
	if( oneChar != "-" && oneChar != "." && oneChar < "0" || oneChar > "9") 
		{
		return false
		}
	}
return true
}

function AlertInvalid()
{
alert( "One or more fields were left blank\nOr one of the values given isnt a number\nFill in all fields with numbers\nand retry" );
}