Alphanumeric Validation

Enter text filed only to allow alphabit & Numbers 
function alpha_numeric_validation(arg){
 var valReg = /^[A-Za-z0-9]+$/;
 if(valReg.test( arg ) ) {
  return false;
 } else {
  return true;
 }
}

Alpha Space Validation in JS

Enter text file allow allphabi & space only
function alpha_space_validation(arg){
 var valReg = /^[A-Za-z ]+$/;
 if(valReg.test( arg ) ) {
  return false;
 } else {
  return true;
 }
}

Email Validation - Form field Validate Email Address

alert(email_validation("asasas"))
function email_validation(arg){
 var emailReg = /^([\w-\.]+@([\w-]+\.)+[\w-]{2,4})?$/;
 if( !emailReg.test( arg ) ) {
  return false;
 } else {
  return true;
 }
}