Covert the textbox text to Upper case by javascript:

Change the Lower case letter to upper case in Javascript by Change the focus of textbox; 

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@Code Snippet – Javascript code to convert lower case to upper Textbox

function convertToUpperCase(textBox) {
        if (textBox != null) {

            if (textBox.getValue())

                textBox.setValue(textBox.getValue().toUpperCase());

            else

                textBox.value = textBox.value.toUpperCase();

        }

        return true;

    }

@HTML tag: On blur event

<adp: TextBox ID="tbNameFrench" runat="server" onblur="convertToUpperCase(this)"

                        MaxLength="8"></adp: TextBox>