function eraseTextbox(ctlToErase) {
    var ctl;
    var ctls;
    
    /*
    switch(ctlToErase)
    {
        case 'txtBirthdate':
            // ctl = document.getElementById('<%=txtBirthdate.clientId %>');
    }
     */
           
    ctls = document.getElementsByTagName('input');
    
    for (var i = 0; i < ctls.length; i++) { 
        var name = ctls[i].getAttribute("ID"); 
        var pos = name.indexOf(ctlToErase)
        
        if (pos>=0) {
            ctl = ctls[i]
            break;
        }
    }

    if (ctl != null) {
        //ctl.text='';
        ctl.value='';
    }
    
    return true;
}