//Check for empty or only non visible characters in string
function its_not_visible(string_value) {
 	var not_visible = " \n\r\t"

 	for (var counter = 0; counter < string_value.length; counter++)
	{  current_char = string_value.charAt(counter)
  		if (not_visible.indexOf(current_char) == -1) {
   			return false
  		}
 	}
 	return true
}

//Submit handler can be extended to many more fields
function submit_handler3() {

	if( its_not_visible(document.mi.custom_bname.value) || its_not_visible(document.mi.custom_gname.value) ||
		its_not_visible(document.mi.from.value) || its_not_visible(document.mi.custom_phone.value) ||
		its_not_visible(document.mi.custom_textarea1.value) || its_not_visible(document.mi.custom_textarea2.value) ||
		its_not_visible(document.mi.custom_textarea3.value) || its_not_visible(document.mi.custom_textarea4.value) ||
		its_not_visible(document.mi.custom_textarea5.value) || its_not_visible(document.mi.custom_textarea6.value) ||
		its_not_visible(document.mi.custom_textarea7.value) || its_not_visible(document.mi.custom_textarea8.value) ||
		its_not_visible(document.mi.custom_textarea9.value) || its_not_visible(document.mi.custom_textarea10.value) )
	{
		alert('ALL FIELDS are REQUIRED! Please fill in the missing fields.');
		document.mi.custom_bname.focus() ;
		return false
	}

}