function HideLabel(txtField){
    if(txtField.name=='username'){
        if(txtField.value=='Username')
            txtField.value = '';
        else
            txtField.select();
    }else if(txtField.name=='password'){
        if(txtField.value=='Password'){
            txtField.value = '';
            txtField.type = 'password';
        }
        else{
            txtField.type = 'password';
            txtField.select();
        }
    }
}
function ShowLabel(txtField){
    if(txtField.name=='username'){
        if(txtField.value.trim()=='')
            txtField.value = 'Username';
    }else if(txtField.name=='password'){
        if(txtField.value.trim()==''){
            txtField.value = 'Password';
            txtField.type = 'text';
        }
    }
}