regex only allow letters and spaces code example
Example 1: regex only letters not spaces
var re = /^[A-Za-z]+$/;
Example 2: regex for letters and spaces
/* Note this works with the onkeyup function in html with js */
function lettersandSpacesOnly(input){
var regexs = /[^a-z ]*$/gmi;
input.value = input.value.replace(regexs, "");
}