/* Validate phone number and format.
EX: onkeyup="validatephone(this);" */
function validatephone(n) {
var maintainplus = '';
var numval = n.value
if ( numval.charAt(0)=='+' ){ var maintainplus = '+';}
  curphonevar = numval.replace(/[\\A-Za-z!"£$%^&*_={};:'@#~,.¦\/<>?|`¬\]\[]/g,'');
  n.value = maintainplus + curphonevar;
  var maintainplus = '';
n.focus;
}