What conditions should be applied if i want a text field to take only alphabet as input?

Answer 1

In pure HTML:

<form>
<input pattern="[a-zA-Z]*" required />
</form>

in javascript:

if(myInput.value.match(/[a-zA-Z]*/)){
// everything ok
}else{
// notify the user that he messed up
}

Answer 2

if i apply only html then it wont take white space

Answer 3

you can use the HTML 5 attribute
<form>
<input type='text' pattern='[A-Za-z\\s]*'/>
</form>