validation to allow only alphabets in textControl

validation to allow only alphabets in textControl

Form->design->StringControl->method->validate()

public boolean validate()
{
boolean ret;
;

if(strnfind(this.text(),'ABCDEFGHIJKLMNOPQRSTUVWXYZ',1,strlen(this.text())))
{
info("enter only alfa");
}
else
{
ret = super();
}
return ret;
}