var run=1;  
function ip_check() {
  var ok=1;
  var rc='1px solid #ff0000',orc='1px solid #ced0a2',lc='2px solid #ff0000',olc='1px solid #ced0a2';
  var rb='#FFCCCC',orb='#ffffff';

  if(run) {            
    if(undefined===parent.frames['main'].document.forms['ip_add_form']) {clearInterval(ip_interval); return;} 
    var frm=parent.frames['main'].document.forms['ip_add_form'];
     
    var f_ip=frm.elements['f_ip'];
    var f_ipSymbolsRE=/[^0-9\.]/;
       if(f_ipSymbolsRE.test(f_ip.value))
        {f_ip.style.backgroundColor=rb;ok=0;}else {f_ip.style.backgroundColor=orb;}
      var f_ipRE=/^[0-9]{1,3}[\.][0-9]{1,3}[\.][0-9]{1,3}[\.][0-9]{1,3}$/;
      if(!f_ipRE.test(f_ip.value) && !f_ipSymbolsRE.test(f_ip.value) && f_ip.value)
        {f_ip.style.border=rc;ok=0;}else {f_ip.style.border=orc;} 
    if(!f_ip.value) {f_ip.style.borderLeft=lc;ok=0;} 

    var s_ip=frm.elements['s_ip'];
    var s_ipSymbolsRE=/[^0-9\.]/;
       if(s_ipSymbolsRE.test(s_ip.value))
        {s_ip.style.backgroundColor=rb;ok=0;}else {s_ip.style.backgroundColor=orb;}
      var s_ipRE=/^[0-9]{1,3}[\.][0-9]{1,3}[\.][0-9]{1,3}[\.][0-9]{1,3}$/;
      if(!s_ipRE.test(s_ip.value) && !s_ipSymbolsRE.test(s_ip.value) && s_ip.value)
        {s_ip.style.border=rc;ok=0;}else {s_ip.style.border=orc;} 
    if(!s_ip.value) {s_ip.style.borderLeft=lc;ok=0;} 
    
    if(ok==1)frm.add_ip.disabled=false;else frm.add_ip.disabled=true;
  }
}