function change_couleur(element){
     element.style.borderColor = "#e1e1e1"
     document.getElementById(element.id +"_etoil").style.color = "#353434"
 }

 function validate_form(form){
     var valid = true
     form.nom.style.borderColor = "#e1e1e1"
     form.email.style.borderColor = "#e1e1e1"
     form.msg.style.borderColor = "#e1e1e1"
     
     document.getElementById("nom_etoil").style.color = "#353434"
     document.getElementById("email_etoil").style.color = "#353434"
     document.getElementById("msg_etoil").style.color = "#353434"
     
     if("" == form.nom.value){
         valid = false
         document.getElementById("nom_etoil").style.color = "#f00"
         form.nom.style.borderColor = "#f00"
     }
     
     reg_mail = new RegExp("^[a-z0-9._-]+@[a-z0-9._-]{2,}\.[a-z]{2,5}$")
     if(reg_mail.test(form.email.value) == false){
         valid = false
         document.getElementById("email_etoil").style.color = "#f00"
         form.email.style.borderColor = "#f00"
     }
     if("" == form.msg.value){
         valid = false
         document.getElementById("msg_etoil").style.color = "#f00"
         form.msg.style.borderColor = "#f00"
     } 

     if(valid) form.submit()
 }