Question: how to check if string contains only letters and numbers javascript?
Answer: Javascript function to check if a field input contains letters and numbers only // Function to check letters and numbers function alphanumeric(inputtxt) { var letterNumber = /^[0-9a-zA-Z]+$/; if((inputtxt.value.match(letterNumber)) { return true; } else { alert("message"); return false; } } ...  Flowchart: HTML Code <!